X-Git-Url: http://git.uio.no/git/?a=blobdiff_plain;f=MUON%2FAliMUONClusterFinderAZ.cxx;h=1aaed48bdcef79b7424ec04b9a76dc6f8c068535;hb=d7f298ddd49edd7f8f9820f136018736612ec816;hp=1992593fe12bd0f0704577566648cd15672182ee;hpb=0558a292445dee4b12a03c0da583265e759732d6;p=u%2Fmrichter%2FAliRoot.git

diff --git a/MUON/AliMUONClusterFinderAZ.cxx b/MUON/AliMUONClusterFinderAZ.cxx
index 1992593fe12..1aaed48bdce 100644
--- a/MUON/AliMUONClusterFinderAZ.cxx
+++ b/MUON/AliMUONClusterFinderAZ.cxx
@@ -1,64 +1,98 @@
-#include "AliMUONClusterFinderAZ.h"
+/**************************************************************************
+ * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
+ *                                                                        *
+ * Author: The ALICE Off-line Project.                                    *
+ * Contributors are mentioned in the code where appropriate.              *
+ *                                                                        *
+ * Permission to use, copy, modify and distribute this software and its   *
+ * documentation strictly for non-commercial purposes is hereby granted   *
+ * without fee, provided that the above copyright notice appears in all   *
+ * copies and that both the copyright notice and this permission notice   *
+ * appear in the supporting documentation. The authors make no claims     *
+ * about the suitability of this software for any purpose. It is          *
+ * provided "as is" without express or implied warranty.                  *
+ **************************************************************************/
+
+/* $Id$ */
+
+// Clusterizer class developed by A. Zinchenko (Dubna), based on the 
+// Expectation-Maximization algorithm
 
 #include <stdlib.h>
-#include <fcntl.h>
 #include <Riostream.h>
-#include <TROOT.h>
-#include <TCanvas.h>
-#include <TLine.h>
-#include <TTree.h>
 #include <TH2.h>
-#include <TView.h>
-#include <TStyle.h>
 #include <TMinuit.h>
 #include <TMatrixD.h>
 
-#include "AliHeader.h"
+#include "AliMUONClusterFinderAZ.h"
+#include "AliMUONClusterDrawAZ.h"
+#include "AliMUONVGeometryDESegmentation.h"
+#include "AliMUONGeometryModuleTransformer.h"
 #include "AliRun.h"
 #include "AliMUON.h"
-#include "AliMUONChamber.h"
 #include "AliMUONDigit.h"
-#include "AliMUONHit.h"
-#include "AliMUONChamber.h"
 #include "AliMUONRawCluster.h"
 #include "AliMUONClusterInput.h"
 #include "AliMUONPixel.h"
-#include "AliMC.h"
-
-// Clusterizer class developped by Zitchenko (Dubna)
-//
-//
-//
-
+#include "AliMUONMathieson.h"
+#include "AliLog.h"
 
 ClassImp(AliMUONClusterFinderAZ)
  
+ const Double_t AliMUONClusterFinderAZ::fgkCouplMin = 1.e-3; // threshold on coupling 
+ const Double_t AliMUONClusterFinderAZ::fgkZeroSuppression = 6; // average zero suppression value
+ const Double_t AliMUONClusterFinderAZ::fgkSaturation = 3000; // average saturation level
  AliMUONClusterFinderAZ* AliMUONClusterFinderAZ::fgClusterFinder = 0x0;
  TMinuit* AliMUONClusterFinderAZ::fgMinuit = 0x0;
-
+//FILE *lun1 = fopen("nxny.dat","w");
 
 //_____________________________________________________________________________
-AliMUONClusterFinderAZ::AliMUONClusterFinderAZ(Bool_t draw=0, Int_t iReco=0)
+AliMUONClusterFinderAZ::AliMUONClusterFinderAZ(Bool_t draw)
+  : AliMUONClusterFinderVS()
 {
 // Constructor
-  for (Int_t i=0; i<4; i++) {fHist[i] = 0;}
-  fMuonDigits = 0;
-  fSegmentation[1] = fSegmentation[0] = 0; 
-  fgClusterFinder = 0x0;
-  fgMinuit = 0x0; 
-  if (!fgClusterFinder) fgClusterFinder = this;
+  fnPads[0]=fnPads[1]=0;
+  
+  for (Int_t i=0; i<7; i++)
+    for (Int_t j=0; j<fgkDim; j++)
+      fXyq[i][j]= 9999.;
+
+  for (Int_t i=0; i<4; i++)
+    for (Int_t j=0; j<fgkDim; j++) 
+      fPadIJ[i][j]=-1;
+
+  for (Int_t i=0; i<2; i++)
+    for (Int_t j=0; j<fgkDim; j++) 
+      fUsed[i][j] = 0;
+
+  fSegmentation[1] = fSegmentation[0] = 0x0; 
+
+  fZpad = 0;
+  fQtot = 0;
+  fPadBeg[0] = fPadBeg[1] = fCathBeg = fNpar = fnCoupled = 0;
+
   if (!fgMinuit) fgMinuit = new TMinuit(8);
-  fDraw = draw;
-  fReco = iReco;
+  if (!fgClusterFinder) fgClusterFinder = this;
   fPixArray = new TObjArray(20); 
-  /*
-  fPoints = 0;
-  fPhits = 0;
-  fRpoints = 0;
-  fCanvas = 0;
-  fNextCathode = kFALSE; 
-  fColPad = 0;
-  */
+
+  fDebug = 0; //0;
+  fReco = 1;
+  fDraw = 0x0;
+  if (draw) {
+    fDebug = 1;
+    fReco = 0;
+    fDraw = new AliMUONClusterDrawAZ(this);
+  }
+  cout << " *** Running AZ cluster finder *** " << endl;
+}
+
+//_____________________________________________________________________________
+AliMUONClusterFinderAZ::AliMUONClusterFinderAZ(const AliMUONClusterFinderAZ& rhs)
+  : AliMUONClusterFinderVS(rhs)
+{
+// Protected copy constructor
+
+  AliFatal("Not implemented.");
 }
 
 //_____________________________________________________________________________
@@ -66,20 +100,7 @@ AliMUONClusterFinderAZ::~AliMUONClusterFinderAZ()
 {
   // Destructor
   delete fgMinuit; fgMinuit = 0; delete fPixArray; fPixArray = 0;
-  /*
-  // Delete space point structure
-  if (fPoints) fPoints->Delete();
-  delete fPoints;
-  fPoints     = 0;
-  //
-  if (fPhits) fPhits->Delete();
-  delete fPhits;
-  fPhits     = 0;
-  //
-  if (fRpoints) fRpoints->Delete();
-  delete fRpoints;
-  fRpoints     = 0;
-  */
+  delete fDraw;
 }
 
 //_____________________________________________________________________________
@@ -87,547 +108,163 @@ void AliMUONClusterFinderAZ::FindRawClusters()
 {
 // To provide the same interface as in AliMUONClusterFinderVS
 
-  EventLoop (gAlice->GetHeader()->GetEvent(), AliMUONClusterInput::Instance()->Chamber());
+  ResetRawClusters(); 
+  EventLoop (gAlice->GetEvNumber(), fInput->Chamber());
 }
 
 //_____________________________________________________________________________
-void AliMUONClusterFinderAZ::EventLoop(Int_t nev=0, Int_t ch=0)
+void AliMUONClusterFinderAZ::EventLoop(Int_t nev, Int_t ch)
 {
-// Loop over events
+// Loop over digits
   
-  FILE *lun = 0;
-  TCanvas *c1 = 0;
-  TView *view = 0;
-  TH2F *hist = 0;
-  Double_t p1[3]={0}, p2[3];
-  TTree *treeR = 0;
-  if (fDraw) {
-    // File
-    lun = fopen("pool.dat","w");
-    c1 = new TCanvas("c1","Clusters",0,0,600,700);
-    c1->Divide(1,2);
-    new TCanvas("c2","Mlem",700,0,600,350);
-  }
-
-newev:
-  Int_t nparticles = 0, nent;
+  if (fDraw && !fDraw->FindEvCh(nev, ch)) return;
 
-  //Loaders
-  AliRunLoader * rl = AliRunLoader::GetRunLoader();
-  AliLoader * gime  = rl->GetLoader("MUONLoader");
-
-  if (!fReco) nparticles = rl->GetEvent(nev);
-  else nparticles = gAlice->GetMCApp()->GetNtrack();
-  cout << "nev         " << nev <<endl;
-  cout << "nparticles  " << nparticles <<endl;
-  if (nparticles <= 0) return;
-  
-  TTree *treeH = gime->TreeH();
-  Int_t ntracks = (Int_t) treeH->GetEntries();
-  cout<<"ntracks "<<ntracks<<endl;
+  fSegmentation[0] = (AliMUONVGeometryDESegmentation*) fInput->
+    Segmentation2(0)->GetDESegmentation(fInput->DetElemId());
+  fSegmentation[1] = (AliMUONVGeometryDESegmentation*) fInput->
+    Segmentation2(1)->GetDESegmentation(fInput->DetElemId());
     
-  // Get pointers to Alice detectors and Digits containers
-  AliMUON *muon  = (AliMUON*) gAlice->GetModule("MUON");
-  if (!muon) return;
-  //       TClonesArray *Particles = gAlice->Particles();
-  if (!fReco) {
-    treeR = gime->TreeR();
-    if (treeR) {
-      muon->ResetRawClusters();
-      nent = (Int_t) treeR->GetEntries();
-      if (nent != 1) {
-	cout << "Error in MUONdrawClust" << endl;
-	cout << " nent = " <<  nent << " not equal to 1" << endl;
-	//exit(0);
-      }
-    } // if (treeR)
-  } // if (!fReco)
-
-  TTree *treeD = gime->TreeD();
-  //muon->ResetDigits();
-
-  TClonesArray *listMUONrawclust ;
-  AliMUONChamber*       iChamber = 0;
-  
-  // As default draw the first cluster of the chamber #0
-      
-newchamber:
-  if (ch > 9) {if (fReco) return; nev++; ch = 0; goto newev;}
-  //gAlice->ResetDigits();
-  fMuonDigits  = muon->GetMUONData()->Digits(ch);
-  if (fMuonDigits == 0) return;
-  iChamber = &(muon->Chamber(ch));
-  fSegmentation[0] = iChamber->SegmentationModel(1);
-  fSegmentation[1] = iChamber->SegmentationModel(2);
-  fResponse = iChamber->ResponseModel();
-    
-  nent = 0;
- 
-  if (treeD) {
-    nent = (Int_t) treeD->GetEntries();
-    //printf(" entries %d \n", nent);
-  }
-
-  Int_t ndigits[2]={9,9}, nShown[2]={0};
-  for (Int_t i=0; i<2; i++) {
-    for (Int_t j=0; j<kDim; j++) {fUsed[i][j]=kFALSE;}
+  Int_t ndigits[2] = {9,9}, nShown[2] = {0};
+  if (fReco != 2) { // skip initialization for the combined cluster / track
+    fCathBeg = fPadBeg[0] = fPadBeg[1] = 0;
+    for (Int_t i = 0; i < 2; i++) {
+      for (Int_t j = 0; j < fgkDim; j++) { fUsed[i][j] = kFALSE; }
+    }
   }
 
 next:
-  if (ndigits[0] == nShown[0] && ndigits[1] == nShown[1]) {
-    // No more clusters
-    if (fReco) return;
-    ch++;
-    goto newchamber; // next chamber
-  }
+  if (fReco == 2 && (nShown[0] || nShown[1])) return; // only one precluster for the combined finder
+  if (ndigits[0] == nShown[0] && ndigits[1] == nShown[1]) return;
+
   Float_t xpad, ypad, zpad, zpad0;
-  TLine *line[99]={0};
-  Int_t nLine = 0;
   Bool_t first = kTRUE;
-  cout << " *** Event # " << nev << " chamber: " << ch << endl;
+  if (fDebug) cout << " *** Event # " << nev << " chamber: " << ch << endl;
   fnPads[0] = fnPads[1] = 0;
-  for (Int_t i=0; i<kDim; i++) {fPadIJ[1][i] = 0;}
-  //for (Int_t iii = 0; iii<999; iii++) { 
-  for (Int_t iii = 0; iii<2; iii++) { 
-    Int_t cath = TMath::Odd(iii);
-    gAlice->ResetDigits();
-    treeD->GetEvent(cath);
-    fMuonDigits  = muon->GetMUONData()->Digits(ch);
+  for (Int_t i = 0; i < fgkDim; i++) fPadIJ[1][i] = 0; 
 
-    ndigits[cath] = fMuonDigits->GetEntriesFast();
-    if (!ndigits[0] && !ndigits[1]) {if (fReco) return; ch++; goto newchamber;}
+  for (Int_t iii = fCathBeg; iii < 2; iii++) { 
+    Int_t cath = TMath::Odd(iii);
+    ndigits[cath] = fInput->NDigits(cath); 
+    if (!ndigits[0] && !ndigits[1]) return;
     if (ndigits[cath] == 0) continue;
-    cout << " ndigits: " << ndigits[cath] << " " << cath << endl;
+    if (fDebug) cout << " ndigits: " << ndigits[cath] << " " << cath << endl;
 
     AliMUONDigit  *mdig;
     Int_t digit;
 
     Bool_t eEOC = kTRUE; // end-of-cluster
-    for (digit = 0; digit < ndigits[cath]; digit++) {
-      mdig    = (AliMUONDigit*)fMuonDigits->UncheckedAt(digit);
-      if (mdig->Cathode() != cath) continue;
+    for (digit = fPadBeg[cath]; digit < ndigits[cath]; digit++) {
+      mdig = AliMUONClusterInput::Instance()->Digit(cath,digit); 
       if (first) {
 	// Find first unused pad
 	if (fUsed[cath][digit]) continue;
-	fSegmentation[cath]->GetPadC(mdig->PadX(),mdig->PadY(),xpad,ypad,zpad0);
+	//if (!fSegmentation[cath]->GetPadC(fInput->DetElemId(),mdig->PadX(),mdig->PadY(),xpad,ypad,zpad0)) { 
+	if (!fSegmentation[cath]->HasPad(mdig->PadX(), mdig->PadY())) {
+	  // Handle "non-existing" pads
+	  fUsed[cath][digit] = kTRUE; 
+	  continue; 
+	} 
+	fSegmentation[cath]->GetPadC(mdig->PadX(), mdig->PadY(), xpad, ypad, zpad0); 
       } else {
 	if (fUsed[cath][digit]) continue;
-	fSegmentation[cath]->GetPadC(mdig->PadX(),mdig->PadY(),xpad,ypad,zpad);
-	if (TMath::Abs(zpad-zpad0)>0.1) continue; // different slats
+	//if (!fSegmentation[cath]->GetPadC(fInput->DetElemId(),mdig->PadX(),mdig->PadY(),xpad,ypad,zpad)) {
+	if (!fSegmentation[cath]->HasPad(mdig->PadX(), mdig->PadY())) {
+	  // Handle "non-existing" pads
+	  fUsed[cath][digit] = kTRUE; 
+	  continue; 
+	} 
+	fSegmentation[cath]->GetPadC(mdig->PadX(), mdig->PadY(), xpad, ypad, zpad); 
+	//if (TMath::Abs(zpad-zpad0) > 0.1) continue; // different slats
 	// Find a pad overlapping with the cluster
 	if (!Overlap(cath,mdig)) continue;
       }
       // Add pad - recursive call
       AddPad(cath,digit);
+      //AZ !!!!!! Temporary fix of St1 overlap regions !!!!!!!! 
+      /*
+      if (cath && ch < 2) {
+	Int_t npads = fnPads[0] + fnPads[1] - 1;
+	Int_t cath1 = fPadIJ[0][npads];
+	Int_t idig = TMath::Nint (fXyq[5][npads]);
+	mdig = AliMUONClusterInput::Instance()->Digit(cath1,idig);
+	//fSegmentation[cath1]->GetPadC(fInput->DetElemId(),mdig->PadX(),mdig->PadY(),xpad,ypad,zpad);
+	fSegmentation[cath1]->GetPadC(mdig->PadX(), mdig->PadY(), xpad, ypad, zpad);
+	if (TMath::Abs(zpad-zpad0) > 0.1) zpad0 = zpad;
+      }	
+      */
       eEOC = kFALSE;
       if (digit >= 0) break;
     }
     if (first && eEOC) {
       // No more unused pads 
       if (cath == 0) continue; // on cathode #0 - check #1
-      else {
-	// No more clusters
-	if (fReco) return;
-	ch++;
-	goto newchamber; // next chamber
-      }
+      else return; // No more clusters
     }
     if (eEOC) break; // cluster found
     first = kFALSE;
-    cout << " nPads: " << fnPads[cath] << " " << nShown[cath]+fnPads[cath] << " " << cath << endl;
+    if (fDebug) cout << " nPads: " << fnPads[cath] << " " << nShown[cath]+fnPads[cath] << " " << cath << endl;
   } // for (Int_t iii = 0;
 
-  
-  if (fReco) goto skip;
-  char hName[4];
-  for (Int_t cath = 0; cath<2; cath++) {
-    // Build histograms
-    if (fHist[cath*2]) {fHist[cath*2]->Delete(); fHist[cath*2] = 0;}
-    if (fHist[cath*2+1]) {fHist[cath*2+1]->Delete(); fHist[cath*2+1] = 0;}
-    if (fnPads[cath] == 0) continue; // cluster on one cathode only
-    Float_t wxMin=999, wxMax=0, wyMin=999, wyMax=0; 
-    Int_t minDx=0, maxDx=0, minDy=0, maxDy=0;
-    for (Int_t i=0; i<fnPads[0]+fnPads[1]; i++) {
-      if (fPadIJ[0][i] != cath) continue;
-      if (fXyq[3][i] < wxMin) {wxMin = fXyq[3][i]; minDx = i;}
-      if (fXyq[3][i] > wxMax) {wxMax = fXyq[3][i]; maxDx = i;}
-      if (fXyq[4][i] < wyMin) {wyMin = fXyq[4][i]; minDy = i;}
-      if (fXyq[4][i] > wyMax) {wyMax = fXyq[4][i]; maxDy = i;}
-    }
-    cout << minDx << maxDx << minDy << maxDy << endl;
-    Int_t nx, ny, padSize;
-    Float_t xmin=9999, xmax=-9999, ymin=9999, ymax=-9999;
-    if (TMath::Nint(fXyq[3][minDx]*1000) == TMath::Nint(fXyq[3][maxDx]*1000) &&
-	TMath::Nint(fXyq[4][minDy]*1000) == TMath::Nint(fXyq[4][maxDy]*1000)) {
-      // the same segmentation
-      cout << " Same" << endl;
-      cout << fXyq[3][minDx] << " " << fXyq[3][maxDx] << " " << fXyq[4][minDy] << " " << fXyq[4][maxDy] << endl;
-      for (Int_t i=0; i<fnPads[0]+fnPads[1]; i++) {
-	if (fPadIJ[0][i] != cath) continue;
-	if (fXyq[0][i] < xmin) xmin = fXyq[0][i];
-	if (fXyq[0][i] > xmax) xmax = fXyq[0][i];
-	if (fXyq[1][i] < ymin) ymin = fXyq[1][i];
-	if (fXyq[1][i] > ymax) ymax = fXyq[1][i];
-      }
-      xmin -= fXyq[3][minDx]; xmax += fXyq[3][minDx];
-      ymin -= fXyq[4][minDy]; ymax += fXyq[4][minDy];
-      nx = TMath::Nint ((xmax-xmin)/wxMin/2);
-      ny = TMath::Nint ((ymax-ymin)/wyMin/2);
-      sprintf(hName,"h%d",cath*2);
-      fHist[cath*2] = new TH2F(hName,"cluster",nx,xmin,xmax,ny,ymin,ymax);
-      cout << fHist[cath*2] << " " << fnPads[cath] << endl;
-      for (Int_t i=0; i<fnPads[0]+fnPads[1]; i++) {
-	if (fPadIJ[0][i] != cath) continue;
-	fHist[cath*2]->Fill(fXyq[0][i],fXyq[1][i],fXyq[2][i]);
-	//cout << fXyq[0][i] << fXyq[1][i] << fXyq[2][i] << endl;
-      }
-    } else {
-      // different segmentation in the cluster
-      cout << " Different" << endl;
-      cout << fXyq[3][minDx] << " " << fXyq[3][maxDx] << " " << fXyq[4][minDy] << " " << fXyq[4][maxDy] << endl;
-      Int_t nOK = 0;
-      Int_t indx, locMin, locMax;
-      if (TMath::Nint(fXyq[3][minDx]*1000) != TMath::Nint(fXyq[3][maxDx]*1000)) {
-	// different segmentation along x
-	indx = 0;
-	locMin = minDx;
-	locMax = maxDx;
-      } else {
-	// different segmentation along y
-	indx = 1;
-	locMin = minDy;
-	locMax = maxDy;
-      }
-      Int_t loc = locMin;
-      for (Int_t i=0; i<2; i++) {
-	// loop over different pad sizes
-	if (i>0) loc = locMax;
-	padSize = TMath::Nint(fXyq[indx+3][loc]*1000);
-	xmin = 9999; xmax = -9999; ymin = 9999; ymax = -9999;
-	for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
-	  if (fPadIJ[0][j] != cath) continue;
-	  if (TMath::Nint(fXyq[indx+3][j]*1000) != padSize) continue;
-	  nOK++;
-	  xmin = TMath::Min (xmin,fXyq[0][j]);
-	  xmax = TMath::Max (xmax,fXyq[0][j]);
-	  ymin = TMath::Min (ymin,fXyq[1][j]);
-	  ymax = TMath::Max (ymax,fXyq[1][j]);
-	}
-	xmin -= fXyq[3][loc]; xmax += fXyq[3][loc];
-	ymin -= fXyq[4][loc]; ymax += fXyq[4][loc];
-	nx = TMath::Nint ((xmax-xmin)/fXyq[3][loc]/2);
-	ny = TMath::Nint ((ymax-ymin)/fXyq[4][loc]/2);
-	sprintf(hName,"h%d",cath*2+i);
-	fHist[cath*2+i] = new TH2F(hName,"cluster",nx,xmin,xmax,ny,ymin,ymax);
-	for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
-	  if (fPadIJ[0][j] != cath) continue;
-	  if (TMath::Nint(fXyq[indx+3][j]*1000) != padSize) continue;
-	  fHist[cath*2+i]->Fill(fXyq[0][j],fXyq[1][j],fXyq[2][j]);
-	}
-      } // for (Int_t i=0;
-      if (nOK != fnPads[cath]) cout << " *** Too many segmentations: nPads, nOK " << fnPads[cath] << " " << nOK << endl;
-    } // if (TMath::Nint(fXyq[3][minDx]*1000)
-  } // for (Int_t cath = 0;
-	
-  // Draw histograms and coordinates
-  for (Int_t cath=0; cath<2; cath++) {
-    if (cath == 0) ModifyHistos();
-    if (fnPads[cath] == 0) continue; // cluster on one cathode only
-    if (fDraw) {
-      c1->cd(cath+1);
-      gPad->SetTheta(55);
-      gPad->SetPhi(30);
-      Double_t x, y, x0, y0, r1=999, r2=0;
-      if (fHist[cath*2+1]) {
-	// 
-	x0 = fHist[cath*2]->GetXaxis()->GetXmin() - 1000*TMath::Cos(30*TMath::Pi()/180);
-	y0 = fHist[cath*2]->GetYaxis()->GetXmin() - 1000*TMath::Sin(30*TMath::Pi()/180);
-	r1 = 0;
-	Int_t ihist=cath*2;
-	for (Int_t iy=1; iy<=fHist[ihist]->GetNbinsY(); iy++) {
-	  y = fHist[ihist]->GetYaxis()->GetBinCenter(iy) 
-	    + fHist[ihist]->GetYaxis()->GetBinWidth(iy);
-	  for (Int_t ix=1; ix<=fHist[ihist]->GetNbinsX(); ix++) {
-	    if (fHist[ihist]->GetCellContent(ix,iy) > 0.1) {
-	      x = fHist[ihist]->GetXaxis()->GetBinCenter(ix)
-		+ fHist[ihist]->GetXaxis()->GetBinWidth(ix);
-	      r1 = TMath::Max (r1,TMath::Sqrt((x-x0)*(x-x0)+(y-y0)*(y-y0)));
-	    }
-	  }
-	}
-	ihist = cath*2 + 1 ;
-	for (Int_t iy=1; iy<=fHist[ihist]->GetNbinsY(); iy++) {
-	  y = fHist[ihist]->GetYaxis()->GetBinCenter(iy)
-	    + fHist[ihist]->GetYaxis()->GetBinWidth(iy);
-	  for (Int_t ix=1; ix<=fHist[ihist]->GetNbinsX(); ix++) {
-	    if (fHist[ihist]->GetCellContent(ix,iy) > 0.1) {
-	      x = fHist[ihist]->GetXaxis()->GetBinCenter(ix)
-		+ fHist[ihist]->GetXaxis()->GetBinWidth(ix);
-	      r2 = TMath::Max (r2,TMath::Sqrt((x-x0)*(x-x0)+(y-y0)*(y-y0)));
-	    }
-	  }
-	}
-	cout << r1 << " " << r2 << endl;
-      } // if (fHist[cath*2+1])
-      if (r1 > r2) {
-	//fHist[cath*2]->Draw("lego1");
-	fHist[cath*2]->Draw("lego1Fb");
-	//if (fHist[cath*2+1]) fHist[cath*2+1]->Draw("lego1SameAxisBb");
-	if (fHist[cath*2+1]) fHist[cath*2+1]->Draw("lego1SameAxisBbFb");
-      } else {
-	//fHist[cath*2+1]->Draw("lego1");
-	fHist[cath*2+1]->Draw("lego1Fb");
-	//fHist[cath*2]->Draw("lego1SameAxisBb");
-	fHist[cath*2]->Draw("lego1SameAxisFbBb");
-      }
-      c1->Update();
-    } // if (fDraw)
-  } // for (Int_t cath = 0;
-
-  // Draw generated hits
-  Double_t xNDC[6];
-  hist = fHist[0] ? fHist[0] : fHist[2];
-  p2[2] = hist->GetMaximum();
-  view = 0;
-  if (c1) view = c1->Pad()->GetView();
-  cout << " *** GEANT hits *** " << endl;
-  fnMu = 0;
-  Int_t ix, iy, iok;
-  for (Int_t i=0; i<ntracks; i++) {
-    treeH->GetEvent(i);
-    for (AliMUONHit* mHit=(AliMUONHit*)muon->FirstHit(-1); 
-	 mHit;
-	 mHit=(AliMUONHit*)muon->NextHit()) {
-      if (mHit->Chamber() != ch+1) continue;  // chamber number
-      if (TMath::Abs(mHit->Z()-zpad0) > 1) continue; // different slat
-      p2[0] = p1[0] = mHit->X();        // x-pos of hit
-      p2[1] = p1[1] = mHit->Y();        // y-pos
-      if (p1[0] < hist->GetXaxis()->GetXmin() || 
-	  p1[0] > hist->GetXaxis()->GetXmax()) continue;
-      if (p1[1] < hist->GetYaxis()->GetXmin() || 
-	  p1[1] > hist->GetYaxis()->GetXmax()) continue;
-      // Check if track comes thru pads with signal
-      iok = 0;
-      for (Int_t ihist=0; ihist<4; ihist++) {
-	if (!fHist[ihist]) continue;
-	ix = fHist[ihist]->GetXaxis()->FindBin(p1[0]);
-	iy = fHist[ihist]->GetYaxis()->FindBin(p1[1]);
-	if (fHist[ihist]->GetCellContent(ix,iy) > 0.5) {iok = 1; break;}
-      }
-      if (!iok) continue;
-      gStyle->SetLineColor(1);
-      if (TMath::Abs((Int_t)mHit->Particle()) == 13) {
-	gStyle->SetLineColor(4);
-	fnMu++;
-	if (fnMu <= 2) {
-	  fxyMu[fnMu-1][0] = p1[0];
-	  fxyMu[fnMu-1][1] = p1[1];
-	}
-      }	    
-      printf(" X=%10.4f, Y=%10.4f, Z=%10.4f\n",p1[0],p1[1],mHit->Z());
-      if (view) {
-	view->WCtoNDC(p1, &xNDC[0]);
-	view->WCtoNDC(p2, &xNDC[3]);
-	for (Int_t ipad=1; ipad<3; ipad++) {
-	  c1->cd(ipad);
-	  //c1->DrawLine(xpad[0],xpad[1],xpad[3],xpad[4]);
-	  line[nLine] = new TLine(xNDC[0],xNDC[1],xNDC[3],xNDC[4]);
-	  line[nLine++]->Draw();
-	}
-      }
-    } // for (AliMUONHit* mHit=
-  } // for (Int_t i=0; i<ntracks;
-
-  // Draw reconstructed coordinates
-  listMUONrawclust  = muon->GetMUONData()->RawClusters(ch);
-  treeR->GetEvent(ch);
-  //cout << listMUONrawclust  << " " << listMUONrawclust ->GetEntries() << endl;
-  AliMUONRawCluster *mRaw;
-  gStyle->SetLineColor(3);
-  cout << " *** Reconstructed hits *** " << endl;
-  for (Int_t i=0; i<listMUONrawclust ->GetEntries(); i++) {
-    mRaw = (AliMUONRawCluster*)listMUONrawclust ->UncheckedAt(i);
-    if (TMath::Abs(mRaw->GetZ(0)-zpad0) > 1) continue; // different slat
-    p2[0] = p1[0] = mRaw->GetX(0);        // x-pos of hit
-    p2[1] = p1[1] = mRaw->GetY(0);        // y-pos
-    if (p1[0] < hist->GetXaxis()->GetXmin() || 
-	p1[0] > hist->GetXaxis()->GetXmax()) continue;
-    if (p1[1] < hist->GetYaxis()->GetXmin() || 
-	p1[1] > hist->GetYaxis()->GetXmax()) continue;
-    /*
-      treeD->GetEvent(cath);
-      cout << mRaw->fMultiplicity[0] << mRaw->fMultiplicity[1] << endl;
-      for (Int_t j=0; j<mRaw->fMultiplicity[cath]; j++) {
-      Int_t digit = mRaw->fIndexMap[j][cath];
-      cout << ((AliMUONDigit*)fMuonDigits->UncheckedAt(digit))->Signal() << endl;
-      }
-    */
-    // Check if track comes thru pads with signal
-    iok = 0;
-    for (Int_t ihist=0; ihist<4; ihist++) {
-      if (!fHist[ihist]) continue;
-      ix = fHist[ihist]->GetXaxis()->FindBin(p1[0]);
-      iy = fHist[ihist]->GetYaxis()->FindBin(p1[1]);
-      if (fHist[ihist]->GetCellContent(ix,iy) > 0.5) {iok = 1; break;}
-    }
-    if (!iok) continue;
-    printf(" X=%10.4f, Y=%10.4f, Z=%10.4f\n",p1[0],p1[1],mRaw->GetZ(0));
-    if (view) {
-      view->WCtoNDC(p1, &xNDC[0]);
-      view->WCtoNDC(p2, &xNDC[3]);
-      for (Int_t ipad=1; ipad<3; ipad++) {
-	c1->cd(ipad);
-	line[nLine] = new TLine(xNDC[0],xNDC[1],xNDC[3],xNDC[4]);
-	line[nLine++]->Draw();
-      }
-    }
-  } // for (Int_t i=0; i<listMUONrawclust ->GetEntries();
-  if (fDraw) c1->Update();
+  fZpad = zpad0;
+  if (fDraw) fDraw->DrawCluster(); 
 
-skip:
   // Use MLEM for cluster finder
-  fZpad = zpad0;
   Int_t nMax = 1, localMax[100], maxPos[100];
   Double_t maxVal[100];
   
   if (CheckPrecluster(nShown)) {
     BuildPixArray();
-    if (fnPads[0]+fnPads[1] > 50) nMax = FindLocalMaxima(localMax, maxVal);
+    //*
+    if (fnPads[0]+fnPads[1] > 50) nMax = FindLocalMaxima(fPixArray, localMax, maxVal);
+    if (nMax > 1) TMath::Sort(nMax, maxVal, maxPos, kTRUE); // in decreasing order
+    Int_t iSimple = 0, nInX = -1, nInY;
+    PadsInXandY(nInX, nInY);
+    if (fDebug) cout << "Pads in X and Y: " << nInX << " " << nInY << endl;
+    if (nMax == 1 && nInX < 4 && nInY < 4) iSimple = 1; //1; // simple cluster
+    //*/
+    /* For test
+    Int_t iSimple = 0, nInX = -1, nInY;
+    PadsInXandY(nInX, nInY);
+    if (fDebug) cout << "Pads in X and Y: " << nInX << " " << nInY << endl;
+    if (nMax == 1 && nInX < 4 && nInY < 4) iSimple = 1; //1; // simple cluster
+    if (!iSimple) nMax = FindLocalMaxima(fPixArray, localMax, maxVal);
+    nMax = 1;
     if (nMax > 1) TMath::Sort(nMax, maxVal, maxPos, kTRUE); // in decreasing order
+    */
     for (Int_t i=0; i<nMax; i++) {
       if (nMax > 1) FindCluster(localMax, maxPos[i]);
-      if (!MainLoop()) cout << " MainLoop failed " << endl;
+      if (!MainLoop(iSimple)) AliWarning(Form(" MainLoop failed "));
       if (i < nMax-1) {
 	for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
 	  if (fPadIJ[1][j] == 0) continue; // pad charge was not modified
 	  fPadIJ[1][j] = 0;
-	  fXyq[2][j] = fXyq[5][j]; // use backup charge value
+	  fXyq[2][j] = fXyq[6][j]; // use backup charge value
 	}
       }
-    }
-  }
-  if (fReco) goto next;
-
-  for (Int_t i=0; i<fnMu; i++) {
-    // Check again if muon come thru the used pads (due to extra splitting)
-    for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
-      if (TMath::Abs(fxyMu[i][0]-fXyq[0][j])<fXyq[3][j] && 
-	  TMath::Abs(fxyMu[i][1]-fXyq[1][j])<fXyq[4][j]) {
-	printf("%12.3e %12.3e %12.3e %12.3e\n",fxyMu[i][2],fxyMu[i][3],fxyMu[i][4],fxyMu[i][5]);
-	if (lun) fprintf(lun,"%4d %2d %12.3e %12.3e %12.3e %12.3e\n",nev,ch,fxyMu[i][2],fxyMu[i][3],fxyMu[i][4],fxyMu[i][5]);
-	break;
-      }
-    }
-  } // for (Int_t i=0; i<fnMu;
-
-  // What's next?
-  char command[8];
-  cout << " What is next? " << endl;
-  command[0] = ' '; 
-  if (fDraw) gets(command);
-  if (command[0] == 'n' || command[0] == 'N') {nev++; goto newev;} // next event 
-  else if (command[0] == 'q' || command[0] == 'Q') {fclose(lun); return;} // exit display 
-  //else if (command[0] == 'r' || command[0] == 'R') goto redraw; // redraw points
-  else if (command[0] == 'c' || command[0] == 'C') {
-    // new chamber
-    sscanf(command+1,"%d",&ch);
-    goto newchamber;
-  } 
-  else if (command[0] == 'e' || command[0] == 'E') {
-    // new event
-    sscanf(command+1,"%d",&nev);
-    goto newev;
-  } 
-  else goto next; // Next cluster
-}
-
-//_____________________________________________________________________________
-void AliMUONClusterFinderAZ::ModifyHistos(void)
-{
-  // Modify histograms to bring them to the same size
-  Int_t nhist = 0;
-  Float_t hlim[4][4], hbin[4][4]; // first index - xmin, xmax, ymin, ymax
-  Float_t binMin[4] = {999,999,999,999};
-
-  for (Int_t i=0; i<4; i++) {
-    if (!fHist[i]) continue;
-    hlim[0][nhist] = fHist[i]->GetXaxis()->GetXmin(); // xmin
-    hlim[1][nhist] = fHist[i]->GetXaxis()->GetXmax(); // xmax
-    hlim[2][nhist] = fHist[i]->GetYaxis()->GetXmin(); // ymin
-    hlim[3][nhist] = fHist[i]->GetYaxis()->GetXmax(); // ymax
-    hbin[0][nhist] = hbin[1][nhist] = fHist[i]->GetXaxis()->GetBinWidth(1);
-    hbin[2][nhist] = hbin[3][nhist] = fHist[i]->GetYaxis()->GetBinWidth(1);
-    binMin[0] = TMath::Min(binMin[0],hbin[0][nhist]);
-    binMin[2] = TMath::Min(binMin[2],hbin[2][nhist]);
-    nhist++;
-  }
-  binMin[1] = binMin[0];
-  binMin[3] = binMin[2];
-  cout << " Nhist: " << nhist << endl;
-
-  Int_t imin, imax;
-  for (Int_t lim=0; lim<4; lim++) {
-    while (1) {
-      imin = TMath::LocMin(nhist,hlim[lim]);
-      imax = TMath::LocMax(nhist,hlim[lim]);
-      if (TMath::Abs(hlim[lim][imin]-hlim[lim][imax])<0.01*binMin[lim]) break;
-      if (lim == 0 || lim == 2) {
-	// find lower limit
-	hlim[lim][imax] -= hbin[lim][imax];
-      } else {
-	// find upper limit
-	hlim[lim][imin] += hbin[lim][imin];
-      }
-    } // while (1)
-  }
-    
-  // Rebuild histograms 
-  nhist = 0;
-  TH2F *hist = 0;
-  Int_t nx, ny;
-  Double_t x, y, cont, cmax=0;
-  char hName[4];
-  for (Int_t ihist=0; ihist<4; ihist++) {
-    if (!fHist[ihist]) continue;
-    nx = TMath::Nint((hlim[1][nhist]-hlim[0][nhist])/hbin[0][nhist]);
-    ny = TMath::Nint((hlim[3][nhist]-hlim[2][nhist])/hbin[2][nhist]);
-    //hist =  new TH2F("h","hist",nx,hlim[0][nhist],hlim[1][nhist],ny,hlim[2][nhist],hlim[3][nhist]);
-    sprintf(hName,"hh%d",ihist);
-    hist =  new TH2F(hName,"hist",nx,hlim[0][nhist],hlim[1][nhist],ny,hlim[2][nhist],hlim[3][nhist]);
-    for (Int_t i=1; i<=fHist[ihist]->GetNbinsX(); i++) {
-      x = fHist[ihist]->GetXaxis()->GetBinCenter(i);
-      for (Int_t j=1; j<=fHist[ihist]->GetNbinsY(); j++) {
-	y = fHist[ihist]->GetYaxis()->GetBinCenter(j);
-	cont = fHist[ihist]->GetCellContent(i,j);
-	hist->Fill(x,y,cont);
-      }
-    }
-    cmax = TMath::Max (cmax,hist->GetMaximum());
-    fHist[ihist]->Delete();
-    fHist[ihist] = new TH2F(*hist);
-    hist->Delete(); 
-    nhist++;
-  }
-  printf("%f \n",cmax);
-
-  for (Int_t ihist=0; ihist<4; ihist++) {
-    if (!fHist[ihist]) continue;
-    fHist[ihist]->SetMaximum(cmax);
+    } // for (Int_t i=0; i<nMax;
+    if (nMax > 1) ((TH2D*) gROOT->FindObject("anode"))->Delete();
+    TH2D *mlem = (TH2D*) gROOT->FindObject("mlem");
+    if (mlem) mlem->Delete();
   }
+  if (!fDraw || fDraw->Next()) goto next;
 }
 
 //_____________________________________________________________________________
 void AliMUONClusterFinderAZ::AddPad(Int_t cath, Int_t digit)
 {
   // Add pad to the cluster
-  AliMUONDigit *mdig = (AliMUONDigit*)fMuonDigits->UncheckedAt(digit);
+  AliMUONDigit *mdig = fInput->Digit(cath,digit); 
 
   Int_t charge = mdig->Signal();
   // get the center of the pad
-  Float_t xpad, ypad, zpad;
-  fSegmentation[cath]->GetPadC(mdig->PadX(), mdig->PadY(), xpad, ypad, zpad);
-  
-  Int_t   isec = fSegmentation[cath]->Sector(mdig->PadX(), mdig->PadY());
+  Float_t xpad, ypad, zpad0;
+  //if (!fSegmentation[cath]->GetPadC(fInput->DetElemId(),mdig->PadX(),mdig->PadY(),xpad,ypad,zpad0)) {	  // Handle "non-existing" pads
+  if (!fSegmentation[cath]->HasPad(mdig->PadX(), mdig->PadY())) {
+    fUsed[cath][digit] = kTRUE; 
+    return; 
+  } 
+  fSegmentation[cath]->GetPadC(mdig->PadX(), mdig->PadY(), xpad, ypad, zpad0);
+  Int_t isec = fSegmentation[cath]->Sector(mdig->PadX(), mdig->PadY());
   Int_t nPads = fnPads[0] + fnPads[1];
   fXyq[0][nPads] = xpad;
   fXyq[1][nPads] = ypad;
@@ -635,45 +272,45 @@ void AliMUONClusterFinderAZ::AddPad(Int_t cath, Int_t digit)
   fXyq[3][nPads] = fSegmentation[cath]->Dpx(isec)/2;
   fXyq[4][nPads] = fSegmentation[cath]->Dpy(isec)/2;
   fXyq[5][nPads] = digit;
+  fXyq[6][nPads] = 0;
   fPadIJ[0][nPads] = cath;
   fPadIJ[1][nPads] = 0;
+  fPadIJ[2][nPads] = mdig->PadX();
+  fPadIJ[3][nPads] = mdig->PadY();
   fUsed[cath][digit] = kTRUE;
-  //cout << " bbb " << fXyq[cath][2][nPads] << " " << fXyq[cath][0][nPads] << " " << fXyq[cath][1][nPads] << " " << fXyq[cath][3][nPads] << " " << fXyq[cath][4][nPads] << " " << zpad << " " << nPads << endl;
+  if (fDebug) printf(" bbb %d %d %f %f %f %f %f %4d %3d %3d \n", nPads, cath, xpad, ypad, zpad0, fXyq[3][nPads]*2, fXyq[4][nPads]*2, charge, mdig->PadX(), mdig->PadY());
   fnPads[cath]++;
 
   // Check neighbours
   Int_t nn, ix, iy, xList[10], yList[10];
   AliMUONDigit  *mdig1;
 
-  Int_t ndigits = fMuonDigits->GetEntriesFast();
-  fSegmentation[cath]->Neighbours(mdig->PadX(),mdig->PadY(),&nn,xList,yList); 
-  for (Int_t in=0; in<nn; in++) {
-    ix=xList[in];
-    iy=yList[in];
+  Int_t ndigits = fInput->NDigits(cath); 
+  fSegmentation[cath]->Neighbours(mdig->PadX(), mdig->PadY(), &nn, xList, yList); 
+  for (Int_t in = 0; in < nn; in++) {
+    ix = xList[in];
+    iy = yList[in];
     for (Int_t digit1 = 0; digit1 < ndigits; digit1++) {
       if (digit1 == digit) continue;
-      mdig1 = (AliMUONDigit*)fMuonDigits->UncheckedAt(digit1);
-      if (mdig1->Cathode() != cath) continue;
+      mdig1 = fInput->Digit(cath,digit1); 
       if (!fUsed[cath][digit1] && mdig1->PadX() == ix && mdig1->PadY() == iy) {
 	fUsed[cath][digit1] = kTRUE;
 	// Add pad - recursive call
 	AddPad(cath,digit1);
       }
     } //for (Int_t digit1 = 0;
-  } // for (Int_t in=0;
+  } // for (Int_t in = 0;
 }
 
 //_____________________________________________________________________________
-Bool_t AliMUONClusterFinderAZ::Overlap(Int_t cath, TObject *dig)
+Bool_t AliMUONClusterFinderAZ::Overlap(Int_t cath, AliMUONDigit *mdig)
 {
   // Check if the pad from one cathode overlaps with a pad 
   // in the precluster on the other cathode
 
-  AliMUONDigit *mdig = (AliMUONDigit*) dig;
-
   Float_t xpad, ypad, zpad;
   fSegmentation[cath]->GetPadC(mdig->PadX(), mdig->PadY(), xpad, ypad, zpad);
-  Int_t   isec = fSegmentation[cath]->Sector(mdig->PadX(), mdig->PadY());
+  Int_t isec = fSegmentation[cath]->Sector(mdig->PadX(), mdig->PadY());
 
   Float_t xy1[4], xy12[4];
   xy1[0] = xpad - fSegmentation[cath]->Dpx(isec)/2;
@@ -710,29 +347,27 @@ Bool_t AliMUONClusterFinderAZ::Overlap(Float_t *xy1, Int_t iPad, Float_t *xy12,
   return kTRUE;
 }
 
-//_____________________________________________________________________________
-/*
-Bool_t AliMUONClusterFinderAZ::Overlap(Int_t i, Int_t j, Float_t *xy12, Int_t iSkip)
-{
-  // Check if the pads i and j overlap and return overlap area
-
-  Float_t xy1[4], xy2[4];
-  return Overlap(xy1, xy2, xy12, iSkip);
-}
-*/
 //_____________________________________________________________________________
 Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
 {
   // Check precluster in order to attempt to simplify it (mostly for
   // two-cathode preclusters)
 
-  Int_t i1, i2;
+  Int_t i1, i2, cath=0, digit=0;
   Float_t xy1[4], xy12[4];
   
   Int_t npad = fnPads[0] + fnPads[1];
+  if (npad == 1) { 
+    // Disregard one-pad clusters (leftovers from splitting)
+    nShown[0] += fnPads[0]; 
+    nShown[1] += fnPads[1]; 
+    return kFALSE;
+  }
 
   // If pads have the same size take average of pads on both cathodes 
-  Int_t sameSize = (fnPads[0] && fnPads[1]) ? 1 : 0;
+  //Int_t sameSize = (fnPads[0] && fnPads[1]) ? 1 : 0;
+  Int_t sameSize = 0; //AZ - 17-01-06
+  
   if (sameSize) {
     Double_t xSize = -1, ySize = 0;
     for (Int_t i=0; i<npad; i++) {
@@ -741,7 +376,20 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
       if (TMath::Abs(xSize-fXyq[3][i]) > 1.e-4 ||  TMath::Abs(ySize-fXyq[4][i]) > 1.e-4) { sameSize = 0; break; }
     }
   } // if (sameSize)
-  if (sameSize && (fnPads[0] > 2 || fnPads[1] > 2)) {
+  if (sameSize && fnPads[0] == 1 && fnPads[1] == 1) sameSize = 0; //AZ
+  // Handle shift by half a pad in Station 1
+  if (sameSize) {
+    Int_t cath0 = fPadIJ[0][0];
+    for (Int_t i = 1; i < npad; i++) {
+      if (fPadIJ[0][i] == cath0) continue;
+      Double_t dx = TMath::Abs ((fXyq[0][i] - fXyq[0][0]) / fXyq[3][i] / 2);
+      Int_t idx = (Int_t) TMath::Abs ((fXyq[0][i] - fXyq[0][0]) / fXyq[3][i] / 2);
+      if (TMath::Abs (dx - idx) > 0.001) sameSize = 0;
+      break;
+    }
+  } // if (sameSize)
+   
+  if (sameSize && (fnPads[0] >= 2 || fnPads[1] >= 2)) {
     nShown[0] += fnPads[0];
     nShown[1] += fnPads[1];
     fnPads[0] = fnPads[1] = 0;
@@ -750,6 +398,7 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
       if (fXyq[2][i] < 0) continue; // used pad
       fXyq[2][fnPads[0]] = fXyq[2][i];
       div = 1;
+      cath = fPadIJ[0][i];
       for (Int_t j=i+1; j<npad; j++) {
 	if (fPadIJ[0][j] == fPadIJ[0][i]) continue; // same cathode
 	if (TMath::Abs(fXyq[0][j]-fXyq[0][i]) > 1.e-4) continue;
@@ -757,11 +406,18 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
 	fXyq[2][fnPads[0]] += fXyq[2][j];
 	div = 2;
 	fXyq[2][j] = -2;
+	if (cath) fXyq[5][fnPads[0]] = fXyq[5][j]; // save digit number for cath 0
 	break;
       }
+      // Flag that the digit from the other cathode
+      if (cath && div == 1) fXyq[5][fnPads[0]] = -fXyq[5][i] - 1; 
+      // If low pad charge take the other equal to 0 
+      //if (div == 1 && fXyq[2][fnPads[0]] < fgkZeroSuppression + 1.5*3) div = 2;
       fXyq[2][fnPads[0]] /= div;
       fXyq[0][fnPads[0]] = fXyq[0][i];
       fXyq[1][fnPads[0]] = fXyq[1][i];
+      fPadIJ[2][fnPads[0]] = fPadIJ[2][i];
+      fPadIJ[3][fnPads[0]] = fPadIJ[3][i];
       fPadIJ[0][fnPads[0]++] = 0;
     }
   } // if (sameSize)
@@ -790,19 +446,30 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
     } // for (Int_t i=0;
 
     // Check if all pads overlap
-    Int_t digit=0, cath, nFlags=0;
-    for (Int_t i=0; i<npad; i++) {nFlags += !flags[i];}
-    if (nFlags) cout << " nFlags = " << nFlags << endl;
+    Int_t nFlags=0;
+    for (Int_t i=0; i<npad; i++) {
+      if (flags[i]) continue;
+      nFlags ++;
+      if (fDebug) cout << i << " " << fPadIJ[0][i] << " " << fXyq[0][i] << " " << fXyq[1][i] << endl;
+    }
+    if (fDebug && nFlags) cout << " nFlags = " << nFlags << endl;
     //if (nFlags > 2 || (Float_t)nFlags / npad > 0.2) { // why 2 ??? - empirical choice
     if (nFlags > 0) {
       for (Int_t i=0; i<npad; i++) {
 	if (flags[i]) continue;
 	digit = TMath::Nint (fXyq[5][i]);
 	cath = fPadIJ[0][i];
+	// Check for edge effect (missing pads on the other cathode)
+	Int_t cath1 = TMath::Even(cath), ix, iy;
+	ix = iy = 0;
+        //if (!fSegmentation[cath1]->GetPadI(fInput->DetElemId(),fXyq[0][i],fXyq[1][i],fZpad,ix,iy)) continue;
+	if (!fSegmentation[cath1]->HasPad(fXyq[0][i], fXyq[1][i], fZpad)) continue;
+	if (nFlags == 1 && fXyq[2][i] < fgkZeroSuppression * 3) continue;
 	fUsed[cath][digit] = kFALSE; // release pad
 	fXyq[2][i] = -2;
 	fnPads[cath]--;
       }
+      if (fDraw) fDraw->UpdateCluster(npad);
     } // if (nFlags > 2)
 
     // Check correlations of cathode charges
@@ -812,45 +479,60 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
       for (Int_t i=0; i<npad; i++) {
 	cath = fPadIJ[0][i];
 	if (fXyq[2][i] > 0) sum[cath] += fXyq[2][i];
-	if (fXyq[2][i] > fResponse->MaxAdc()-1) over[cath] = 0;
+	if (fXyq[2][i] > fgkSaturation-1) over[cath] = 0;
       }
-      cout << " Total charge: " << sum[0] << " " << sum[1] << endl;
+      if (fDebug) cout << " Total charge: " << sum[0] << " " << sum[1] << endl;
       if ((over[0] || over[1]) && TMath::Abs(sum[0]-sum[1])/(sum[0]+sum[1])*2 > 1) { // 3 times difference
-	cout << " Release " << endl;
+	if (fDebug) cout << " Release " << endl;
 	// Big difference
-	cath = sum[0]>sum[1] ? 0 : 1;
-	Int_t imax = 0;
-	Double_t cmax=-1;
+	cath = sum[0] > sum[1] ? 0 : 1;
+	Int_t imax = 0, imin = 0;
+	Double_t cmax = -1, cmin = 9999, dxMin = 0, dyMin = 0;
 	Double_t *dist = new Double_t[npad];
-	for (Int_t i=0; i<npad; i++) {
-	  if (fPadIJ[0][i] != cath) continue;
+	for (Int_t i = 0; i < npad; i++) {
+	  if (fPadIJ[0][i] != cath || fXyq[2][i] < 0) continue;
+	  if (fXyq[2][i] < cmin) {
+	    cmin = fXyq[2][i];
+	    imin = i;
+	  }
 	  if (fXyq[2][i] < cmax) continue;
 	  cmax = fXyq[2][i];
 	  imax = i;
 	}
 	// Arrange pads according to their distance to the max, 
 	// normalized to the pad size
-	for (Int_t i=0; i<npad; i++) {
+	for (Int_t i = 0; i < npad; i++) {
 	  dist[i] = 0;
-	  if (fPadIJ[0][i] != cath) continue;
+	  if (fPadIJ[0][i] != cath || fXyq[2][i] < 0) continue;
 	  if (i == imax) continue; 
-	  if (fXyq[2][i] < 0) continue;
-	  dist[i] = (fXyq[0][i]-fXyq[0][imax])*(fXyq[0][i]-fXyq[0][imax])/
-	             fXyq[3][imax]/fXyq[3][imax]/4;
-	  dist[i] += (fXyq[1][i]-fXyq[1][imax])*(fXyq[1][i]-fXyq[1][imax])/
-                      fXyq[4][imax]/fXyq[4][imax]/4;
-	  dist[i] = TMath::Sqrt (dist[i]);
+	  Double_t dx = (fXyq[0][i] - fXyq[0][imax]) / fXyq[3][imax] / 2;
+	  Double_t dy = (fXyq[1][i] - fXyq[1][imax]) / fXyq[4][imax] / 2;
+	  dist[i] = TMath::Sqrt (dx * dx + dy * dy);
+	  if (i == imin) {
+	    cmin = dist[i] + 0.001; // distance to the pad with minimum charge 
+	    dxMin = dx;
+	    dyMin = dy;
+	  }
 	}
 	TMath::Sort(npad, dist, flags, kFALSE); // in increasing order
 	Int_t indx;
 	Double_t xmax = -1;
-	for (Int_t i=0; i<npad; i++) {
+	for (Int_t i = 0; i < npad; i++) {
 	  indx = flags[i];
-	  if (fPadIJ[0][indx] != cath) continue;
-	  if (fXyq[2][indx] < 0) continue;
-	  if (fXyq[2][indx] <= cmax || TMath::Abs(dist[indx]-xmax)<1.e-3) {
+	  if (fPadIJ[0][indx] != cath || fXyq[2][indx] < 0) continue;
+	  if (dist[indx] > cmin) {
+	    // Farther than the minimum pad
+	    Double_t dx = (fXyq[0][indx] - fXyq[0][imax]) / fXyq[3][imax] / 2;
+	    Double_t dy = (fXyq[1][indx] - fXyq[1][imax]) / fXyq[4][imax] / 2;
+	    dx *= dxMin;
+	    dy *= dyMin;
+	    if (dx >= 0 && dy >= 0) continue;
+	    if (TMath::Abs(dx) > TMath::Abs(dy) && dx >= 0) continue;
+	    if (TMath::Abs(dy) > TMath::Abs(dx) && dy >= 0) continue;
+	  }
+	  if (fXyq[2][indx] <= cmax || TMath::Abs(dist[indx]-xmax) < 1.e-3) {
 	    // Release pads
-	    if (TMath::Abs(dist[indx]-xmax)<1.e-3) 
+	    if (TMath::Abs(dist[indx]-xmax) < 1.e-3) 
                 cmax = TMath::Max((Double_t)(fXyq[2][indx]),cmax);
 	    else cmax = fXyq[2][indx];
 	    xmax = dist[indx];
@@ -858,11 +540,39 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
 	    fUsed[cath][digit] = kFALSE; 
 	    fXyq[2][indx] = -2;
 	    fnPads[cath]--;
-	    // xmax = dist[i]; // Bug?
+	  } 
+	} // for (Int_t i = 0; i < npad;
+
+	// Check pad overlaps once more
+	for (Int_t j = 0; j < npad; j++) flags[j] = 0; 
+	for (Int_t k = 0; k < npad; k++) {
+	  if (fXyq[2][k] < 0 || fPadIJ[0][k] != i1) continue;
+	  xy1[0] = fXyq[0][k] - fXyq[3][k];
+	  xy1[1] = fXyq[0][k] + fXyq[3][k];
+	  xy1[2] = fXyq[1][k] - fXyq[4][k];
+	  xy1[3] = fXyq[1][k] + fXyq[4][k];
+	  for (Int_t j = 0; j < npad; j++) {
+	    if (fXyq[2][j] < 0) continue;
+	    if (fPadIJ[0][j] != i2) continue;
+	    if (!Overlap(xy1, j, xy12, 0)) continue;
+	    flags[k] = flags[j] = 1; // mark overlapped pads
+	  } // for (Int_t j = 0;
+	} // for (Int_t k = 0;
+	nFlags = 0;
+	for (Int_t j = 0; j < npad; j++) {
+	  if (fXyq[2][j] < 0 || flags[j]) continue;
+	  nFlags ++;
+	}
+	if (nFlags == fnPads[0] + fnPads[1]) {
+	  // No overlap
+	  for (Int_t j = 0; j < npad; j++) {
+	    if (fXyq[2][j] < 0 || fPadIJ[0][j] != cath) continue;
+	    fXyq[2][j] = -2;
+	    fnPads[cath]--;
 	  }
-	  else break;
-	} 
+	}
 	delete [] dist; dist = 0;
+	if (fDraw) fDraw->UpdateCluster(npad);
       } // TMath::Abs(sum[0]-sum[1])...
     } // if (fnPads[0] && fnPads[1])
     delete [] flags; flags = 0;
@@ -878,7 +588,7 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
     for (Int_t j=end; j>beg; j--) {
       if (fXyq[2][j] < 0) continue;
       end = j - 1;
-      for (Int_t j1=0; j1<2; j1++) {
+      for (Int_t j1=0; j1<4; j1++) {
 	padij = fPadIJ[j1][beg]; 
 	fPadIJ[j1][beg] = fPadIJ[j1][j];
 	fPadIJ[j1][j] = padij;
@@ -893,9 +603,12 @@ Bool_t AliMUONClusterFinderAZ::CheckPrecluster(Int_t *nShown)
     beg++;
   } // while
   npad = fnPads[0] + fnPads[1];
-  if (npad > 500) { cout << " ***** Too large cluster. Give up. " << npad << endl; return kFALSE; }
+  if (npad > 500) { 
+    AliWarning(Form(" *** Too large cluster. Give up. %d ", npad));
+    return kFALSE; 
+  }
   // Back up charge value
-  for (Int_t j=0; j<npad; j++) fXyq[5][j] = fXyq[2][j];
+  for (Int_t j = 0; j < npad; j++) fXyq[6][j] = fXyq[2][j];
 
   return kTRUE;
 }
@@ -928,13 +641,15 @@ void AliMUONClusterFinderAZ::BuildPixArray()
       nPix++;
     }
   } else { // two-cathode precluster    
-    for (Int_t i=0; i<npad; i++) {
+    i1 = fPadIJ[0][0];
+    i2 = TMath::Even (i1);
+    for (Int_t i = 0; i < npad; i++) {
       if (fPadIJ[0][i] != i1) continue;
       xy1[0] = fXyq[0][i] - fXyq[3][i];
       xy1[1] = fXyq[0][i] + fXyq[3][i];
       xy1[2] = fXyq[1][i] - fXyq[4][i];
       xy1[3] = fXyq[1][i] + fXyq[4][i];
-      for (Int_t j=0; j<npad; j++) {
+      for (Int_t j = 1; j < npad; j++) {
 	if (fPadIJ[0][j] != i2) continue;
 	if (!Overlap(xy1, j, xy12, 1)) continue;
 	pixPtr = new AliMUONPixel();
@@ -944,24 +659,36 @@ void AliMUONClusterFinderAZ::BuildPixArray()
 	}
 	pixPtr->SetCharge(TMath::Min (fXyq[2][i],fXyq[2][j])); //charge
 	fPixArray->Add((TObject*)pixPtr);
+	//cout << nPix << " " << pixPtr->Coord(0) << " " << pixPtr->Size(0) << " " << pixPtr->Coord(1) << " " << pixPtr->Size(1) << " " << pixPtr->Charge() << endl;
 	nPix++;
       } // for (Int_t j=0;
     } // for (Int_t i=0;
   } // else
 
-  Float_t wxmin=999, wymin=999;
-  for (Int_t i=0; i<npad; i++) {
-    if (fPadIJ[0][i] == i1) wymin = TMath::Min (wymin,fXyq[4][i]);
-    if (fPadIJ[0][i] == i2) wxmin = TMath::Min (wxmin,fXyq[3][i]);
+  Float_t xPadMin = 999, yPadMin = 999;
+  for (Int_t i = 0; i < npad; i++) {
+    xPadMin = TMath::Min (xPadMin, fXyq[3][i]);
+    yPadMin = TMath::Min (yPadMin, fXyq[4][i]);
+  }
+  if (fDebug) cout << xPadMin << " " << yPadMin << endl;
+
+  Float_t wxmin = 999, wymin = 999;
+  for (Int_t i = 0; i < nPix; i++) {
+    pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
+    wxmin = TMath::Min ((Double_t)wxmin, pixPtr->Size(0));
+    wymin = TMath::Min ((Double_t)wymin, pixPtr->Size(1));
   }
-  cout << wxmin << " " << wymin << endl;
+  if (fDebug) cout << wxmin << " " << wymin << endl;
+  wxmin = TMath::Abs (wxmin - xPadMin/2) > 0.001 ? xPadMin : xPadMin / 2;
+  wymin = TMath::Abs (wymin - yPadMin/2) > 0.001 ? yPadMin : yPadMin / 2;
+  //wxmin = xPadMin; wymin = yPadMin;
 
   // Check if small pixel X-size
-  AjustPixel(wxmin, 0);
+  AdjustPixel(wxmin, 0);
   // Check if small pixel Y-size
-  AjustPixel(wymin, 1);
+  AdjustPixel(wymin, 1);
   // Check if large pixel size
-  AjustPixel(wxmin, wymin);
+  AdjustPixel(wxmin, wymin);
 
   // Remove discarded pixels
   for (Int_t i=0; i<nPix; i++) {
@@ -973,7 +700,7 @@ void AliMUONClusterFinderAZ::BuildPixArray()
   nPix = fPixArray->GetEntriesFast();
 
   if (nPix > npad) {
-    cout << nPix << endl;
+    if (fDebug) cout << nPix << endl;
     // Too many pixels - sort and remove pixels with the lowest signal
     fPixArray->Sort();
     for (Int_t i=npad; i<nPix; i++) {
@@ -989,14 +716,14 @@ void AliMUONClusterFinderAZ::BuildPixArray()
   for (Int_t i=0; i<nPix; i++) {
     pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
     //pixPtr->SetCharge(10);
-    cout << i+1 << " " << pixPtr->Coord(0) << " " << pixPtr->Coord(1) << " " << pixPtr->Size(0) << " " << pixPtr->Size(1) << endl;
+    if (fDebug) cout << i+1 << " " << pixPtr->Coord(0) << " " << pixPtr->Coord(1) << " " << pixPtr->Size(0) << " " << pixPtr->Size(1) << endl;
   }
 }
 
 //_____________________________________________________________________________
-void AliMUONClusterFinderAZ::AjustPixel(Float_t width, Int_t ixy)
+void AliMUONClusterFinderAZ::AdjustPixel(Float_t width, Int_t ixy)
 {
-  // Check if some pixels have small size (ajust if necessary)
+  // Check if some pixels have small size (adjust if necessary)
 
   AliMUONPixel *pixPtr, *pixPtr1 = 0;
   Int_t ixy1 = TMath::Even(ixy);
@@ -1007,7 +734,7 @@ void AliMUONClusterFinderAZ::AjustPixel(Float_t width, Int_t ixy)
     if (pixPtr->Charge() < 1) continue; // discarded pixel
     if (pixPtr->Size(ixy)-width < -1.e-4) {
       // try to merge 
-      cout << " Small X or Y: " << ixy << " " << pixPtr->Size(ixy) << " " << width << " " << pixPtr->Coord(0) << " " << pixPtr->Coord(1) << endl;
+      if (fDebug) cout << i << " Small X or Y: " << ixy << " " << pixPtr->Size(ixy) << " " << width << " " << pixPtr->Coord(0) << " " << pixPtr->Coord(1) << endl;
       for (Int_t j=i+1; j<nPix; j++) {
 	pixPtr1 = (AliMUONPixel*) fPixArray->UncheckedAt(j);
 	if (pixPtr1->Charge() < 1) continue; // discarded pixel
@@ -1015,8 +742,10 @@ void AliMUONClusterFinderAZ::AjustPixel(Float_t width, Int_t ixy)
 	if (TMath::Abs(pixPtr1->Coord(ixy1)-pixPtr->Coord(ixy1)) > 1.e-4) continue; // different rows/columns
 	if (TMath::Abs(pixPtr1->Coord(ixy)-pixPtr->Coord(ixy)) < 2*width) {
 	  // merge
+	  Double_t tmp = pixPtr->Coord(ixy) + pixPtr1->Size(ixy) * 
+	    TMath::Sign (1., pixPtr1->Coord(ixy) - pixPtr->Coord(ixy));
+	  pixPtr->SetCoord(ixy, tmp);
 	  pixPtr->SetSize(ixy, width);
-	  pixPtr->SetCoord(ixy, (pixPtr->Coord(ixy)+pixPtr1->Coord(ixy))/2);
 	  pixPtr->SetCharge(TMath::Min (pixPtr->Charge(),pixPtr1->Charge()));
 	  pixPtr1->SetCharge(0);
 	  pixPtr1 = 0;
@@ -1027,13 +756,15 @@ void AliMUONClusterFinderAZ::AjustPixel(Float_t width, Int_t ixy)
       //else if (pixPtr1->Charge() > 0.5 || i == nPix-1) {
       if (pixPtr1 || i == nPix-1) {
 	// edge pixel - just increase its size
-	cout << " Edge ..." << endl; 
+	if (fDebug) cout << " Edge ..." << endl; 
 	for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
-	  // ???if (fPadIJ[0][j] != i1) continue;
-	  if (TMath::Abs(pixPtr->Coord(ixy1)-fXyq[ixy1][j]) > 1.e-4) continue;
+          //if (fPadIJ[0][j] != ixy1) continue;
+	  //???-check if (TMath::Abs(pixPtr->Coord(ixy1)-fXyq[ixy1][j]) > 1.e-4) continue;
 	  if (pixPtr->Coord(ixy) < fXyq[ixy][j]) 
-	    pixPtr->Shift(ixy, -pixPtr->Size(ixy));
-	  else pixPtr->Shift(ixy, pixPtr->Size(ixy));
+	    //pixPtr->Shift(ixy, -pixPtr->Size(ixy));
+	    pixPtr->Shift(ixy, pixPtr->Size(ixy)-width);
+	  //else pixPtr->Shift(ixy, pixPtr->Size(ixy));
+	  else pixPtr->Shift(ixy, -pixPtr->Size(ixy)+width);
   	  pixPtr->SetSize(ixy, width);
 	  break;
 	}
@@ -1044,43 +775,73 @@ void AliMUONClusterFinderAZ::AjustPixel(Float_t width, Int_t ixy)
 }
   
 //_____________________________________________________________________________
-void AliMUONClusterFinderAZ::AjustPixel(Float_t wxmin, Float_t wymin)
+void AliMUONClusterFinderAZ::AdjustPixel(Float_t wxmin, Float_t wymin)
 {
-  // Check if some pixels have large size (ajust if necessary)
+  // Check if some pixels have large size (adjust if necessary)
 
-  Int_t nx, ny;
-  Int_t nPix = fPixArray->GetEntriesFast();
-  AliMUONPixel *pixPtr, *pixPtr1, pix;
+  Int_t n1[2], n2[2], iOK = 1, nPix = fPixArray->GetEntriesFast();
+  AliMUONPixel *pixPtr, pix;
+  Double_t xy0[2] = {9999, 9999}, wxy[2], dist[2];
 
   // Check if large pixel size
-  for (Int_t i=0; i<nPix; i++) {
+  for (Int_t i = 0; i < nPix; i++) {
     pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
     if (pixPtr->Charge() < 1) continue; // discarded pixel
-    if (pixPtr->Size(0)-wxmin > 1.e-4 || pixPtr->Size(1)-wymin > 1.e-4) {
-      cout << " Different " << pixPtr->Size(0) << " " << wxmin << " " << pixPtr->Size(1) << " " << wymin << endl;
-      pix = *pixPtr;
-      nx = TMath::Nint (pix.Size(0)/wxmin);
-      ny = TMath::Nint (pix.Size(1)/wymin);
-      pix.Shift(0, -pix.Size(0)-wxmin);
-      pix.Shift(1, -pix.Size(1)-wymin);
-      pix.SetSize(0, wxmin);
-      pix.SetSize(1, wymin);
-      for (Int_t ii=0; ii<nx; ii++) {
-	pix.Shift(0, wxmin*2);
-	for (Int_t jj=0; jj<ny; jj++) {
-	  pix.Shift(1, wymin*2);
-	  pixPtr1 = new AliMUONPixel(pix);
-	  fPixArray->Add((TObject*)pixPtr1);
-	}
+    if (pixPtr->Size(0) - wxmin < 1.e-4) {
+      if (xy0[0] > 9998) xy0[0] = pixPtr->Coord(0); // position of a "normal" pixel
+      if (pixPtr->Size(1) - wymin < 1.e-4) { 
+	if (xy0[1] > 9998) xy0[1] = pixPtr->Coord(1); // position of a "normal" pixel
+	continue;
+      } else iOK = 0; // large pixel
+    } else {
+      iOK = 0; // large pixel
+      if (xy0[1] > 9998 && pixPtr->Size(1) - wymin < 1.e-4) xy0[1] = pixPtr->Coord(1); // "normal" pixel
+    }      
+    if (xy0[0] < 9998 && xy0[1] < 9998) break;
+  }
+  if (iOK) return;
+
+  wxy[0] = wxmin;
+  wxy[1] = wymin;
+  //cout << xy0[0] << " " << xy0[1] << endl;
+  for (Int_t i = 0; i < nPix; i++) {
+    pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
+    if (pixPtr->Charge() < 1) continue; // discarded pixel
+    n1[0] = n1[1] = 999;
+    n2[0] = n2[1] = 1;
+    for (Int_t j = 0; j < 2; j++) {
+      if (pixPtr->Size(j) - wxy[j] < 1.e-4) continue;
+      dist[j] = (pixPtr->Coord(j) - xy0[j]) / wxy[j] / 2; // normalized distance to "normal" pixel
+      n2[j] = TMath::Nint (pixPtr->Size(j) / wxy[j]);
+      n1[j] = n2[j] == 1 ? TMath::Nint(dist[j]) : (Int_t)dist[j];
+    }
+    if (n1[0] > 998 && n1[1] > 998) continue;
+    if (fDebug) cout << " Different " << pixPtr->Size(0) << " " << wxy[0] << " "
+		     << pixPtr->Size(1) << " " << wxy[1] <<endl;
+    
+    if (n2[0] > 2 || n2[1] > 2) { 
+      //cout << n2[0] << " " << n2[1] << endl; 
+      if (n2[0] > 2 && n1[0] < 999) n1[0]--;
+      if (n2[1] > 2 && n1[1] < 999) n1[1]--;
+    }
+    //cout << n1[0] << " " << n2[0] << " " << n1[1] << " " << n2[1] << endl;
+    pix = *pixPtr;
+    pix.SetSize(0, wxy[0]); pix.SetSize(1, wxy[1]);
+    //pixPtr->Print();
+    for (Int_t ii = 0; ii < n2[0]; ii++) {
+      if (n1[0] < 999) pix.SetCoord(0, xy0[0] + (n1[0] + TMath::Sign(1.,dist[0]) * ii) * 2 * wxy[0]);
+      for (Int_t jj = 0; jj < n2[1]; jj++) {
+	if (n1[1] < 999) pix.SetCoord(1, xy0[1] + (n1[1] + TMath::Sign(1.,dist[1]) * jj) * 2 * wxy[1]);
+	fPixArray->Add(new AliMUONPixel(pix));
+	//pix.Print();
       }
-      pixPtr->SetCharge(0);
     }
-  } // for (Int_t i=0; i<nPix;
-  return;
+    pixPtr->SetCharge(0);
+  } // for (Int_t i = 0; i < nPix;
 }
 
 //_____________________________________________________________________________
-Bool_t AliMUONClusterFinderAZ::MainLoop()
+Bool_t AliMUONClusterFinderAZ::MainLoop(Int_t iSimple)
 {
   // Repeat MLEM algorithm until pixel size becomes sufficiently small
   
@@ -1089,98 +850,81 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
   Int_t ix, iy;
   //Int_t nn, xList[10], yList[10];
   Int_t nPix = fPixArray->GetEntriesFast();
-  Int_t npadTot = fnPads[0] + fnPads[1], npadOK = 0;
   AliMUONPixel *pixPtr = 0;
   Double_t *coef = 0, *probi = 0; 
-  for (Int_t i=0; i<npadTot; i++) if (fPadIJ[1][i] == 0) npadOK++;
+  AddVirtualPad(); // add virtual pads if necessary
+  Int_t npadTot = fnPads[0] + fnPads[1], npadOK = 0;
+  for (Int_t i = 0; i < npadTot; i++) if (fPadIJ[1][i] == 0) npadOK++;
+  if (fDraw) fDraw->ResetMuon();
 
   while (1) {
 
     mlem = (TH2D*) gROOT->FindObject("mlem");
     if (mlem) mlem->Delete();
     // Calculate coefficients
-    cout << " nPix, npadTot, npadOK " << nPix << " " << npadTot << " " << npadOK << endl;
+    if (fDebug) cout << " nPix, npadTot, npadOK " << nPix << " " << npadTot << " " << npadOK << endl;
 
     // Calculate coefficients and pixel visibilities
     coef = new Double_t [npadTot*nPix];
     probi = new Double_t [nPix];
-    Int_t indx = 0, cath;
-    for (Int_t ipix=0; ipix<nPix; ipix++) {
-      pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(ipix);
-      probi[ipix] = 0;
-      for (Int_t j=0; j<npadTot; j++) {
-	if (fPadIJ[1][j] < 0) { coef[j*nPix+ipix] = 0; continue; }
+    for (Int_t ipix=0; ipix<nPix; ipix++) probi[ipix] = 0;
+    Int_t indx = 0, indx1 = 0, cath = 0;
+
+    for (Int_t j=0; j<npadTot; j++) {
+      indx = j*nPix;
+      if (fPadIJ[1][j] == 0) {
 	cath = fPadIJ[0][j];
-	fSegmentation[cath]->GetPadI(fXyq[0][j],fXyq[1][j],fZpad,ix,iy);
-	fSegmentation[cath]->SetPad(ix,iy);
+	ix = fPadIJ[2][j];
+	iy = fPadIJ[3][j];
+	fSegmentation[cath]->SetPad(ix, iy);
 	/*
-	  fSegmentation[cath]->Neighbours(ix,iy,&nn,xList,yList); 
+	  fSegmentation[cath]->Neighbours(fInput->DetElemId(),ix,iy,&nn,xList,yList); 
 	  if (nn != 4) {
 	  cout << nn << ": ";
 	  for (Int_t i=0; i<nn; i++) {cout << xList[i] << " " << yList[i] << ", ";}
 	  cout << endl;
 	  }
 	*/
-	Double_t sum = 0;
-	fSegmentation[cath]->SetHit(pixPtr->Coord(0),pixPtr->Coord(1),fZpad);
-	sum += fResponse->IntXY(fSegmentation[cath]);
-	indx = j*nPix + ipix;
-	coef[indx] = sum; 
-	probi[ipix] += coef[indx];
-	//cout << j << " " << ipix << " " << coef[indx] << endl;
-      } // for (Int_t j=0;
-      //cout << " prob: " << probi[ipix] << endl;
-      if (probi[ipix] < 0.01) pixPtr->SetCharge(0); // "invisible" pixel
-    } // for (Int_t ipix=0;
+      }
+
+      for (Int_t ipix=0; ipix<nPix; ipix++) {
+	indx1 = indx + ipix;
+	if (fPadIJ[1][j] < 0) { coef[indx1] = 0; continue; }
+	pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(ipix);
+	fSegmentation[cath]->SetHit(pixPtr->Coord(0), pixPtr->Coord(1), fZpad);
+	coef[indx1] = fInput->Mathieson()->IntXY(fInput->DetElemId(),fInput->Segmentation2(cath));
+	probi[ipix] += coef[indx1];
+      } // for (Int_t ipix=0;
+    } // for (Int_t j=0;
+    for (Int_t ipix=0; ipix<nPix; ipix++) if (probi[ipix] < 0.01) pixPtr->SetCharge(0); // "invisible" pixel
 
     // MLEM algorithm
-    Mlem(coef, probi);
+    Mlem(coef, probi, 15);
 
     Double_t xylim[4] = {999, 999, 999, 999};
     for (Int_t ipix=0; ipix<nPix; ipix++) {
       pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(ipix);
+      //cout << ipix+1; pixPtr->Print();
       for (Int_t i=0; i<4; i++) 
 	xylim[i] = TMath::Min (xylim[i], (i%2 ? -1 : 1)*pixPtr->Coord(i/2));
-      //cout << ipix+1; pixPtr->Print();
     }
     for (Int_t i=0; i<4; i++) {
-      xylim[i] -= pixPtr->Size(i/2); cout << (i%2 ? -1 : 1)*xylim[i] << " "; }
-    cout << endl;
+      xylim[i] -= pixPtr->Size(i/2); if (fDebug) cout << (i%2 ? -1 : 1)*xylim[i] << " "; }
+    if (fDebug) cout << endl;
 
-    // Ajust histogram to approximately the same limits as for the pads
+    // Adjust histogram to approximately the same limits as for the pads
     // (for good presentation)
-    //*
-    Float_t xypads[4];
-    if (fHist[0]) {
-      xypads[0] = fHist[0]->GetXaxis()->GetXmin();
-      xypads[1] = -fHist[0]->GetXaxis()->GetXmax();
-      xypads[2] = fHist[0]->GetYaxis()->GetXmin();
-      xypads[3] = -fHist[0]->GetYaxis()->GetXmax();
-      for (Int_t i=0; i<4; i++) {
-	while(1) {
-	  if (xylim[i] < xypads[i]) break;
-	  xylim[i] -= 2*pixPtr->Size(i/2);
-	}
-      }
-    } // if (fHist[0])
-    //*/
+    if (fDraw) fDraw->AdjustHist(xylim, pixPtr);
 
     Int_t nx = TMath::Nint ((-xylim[1]-xylim[0])/pixPtr->Size(0)/2);
     Int_t ny = TMath::Nint ((-xylim[3]-xylim[2])/pixPtr->Size(1)/2);
+    
     mlem = new TH2D("mlem","mlem",nx,xylim[0],-xylim[1],ny,xylim[2],-xylim[3]);
     for (Int_t ipix=0; ipix<nPix; ipix++) {
       pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(ipix);
       mlem->Fill(pixPtr->Coord(0),pixPtr->Coord(1),pixPtr->Charge());
     }
-    //gPad->GetCanvas()->cd(3);
-    if (fDraw) {
-      ((TCanvas*)gROOT->FindObject("c2"))->cd();
-      gPad->SetTheta(55);
-      gPad->SetPhi(30);
-      mlem->Draw("lego1Fb");
-      gPad->Update();
-      gets((char*)&ix);
-    }
+    if (fDraw) fDraw->DrawHist("c2", mlem);
 
     // Check if the total charge of pixels is too low
     Double_t qTot = 0;
@@ -1188,9 +932,10 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
       pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
       qTot += pixPtr->Charge();
     }
-    if (qTot < 1.e-4 || npadOK < 3 && qTot < 50) {
+    if (qTot < 1.e-4 || npadOK < 3 && qTot < 7) {
       delete [] coef; delete [] probi; coef = 0; probi = 0;
       fPixArray->Delete(); 
+      for (Int_t i=0; i<npadTot; i++) if (fPadIJ[1][i] == 0) fPadIJ[1][i] = -1;
       return kFALSE; 
     }
 
@@ -1204,7 +949,7 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
 	pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
 	sum1 += pixPtr->Charge()*coef[j*nPix+i];
       }
-      sum1 = TMath::Min (sum1,(Double_t)fResponse->MaxAdc());
+      sum1 = TMath::Min (sum1,fgkSaturation);
       x = fXyq[0][j];
       y = fXyq[1][j];
       cath = fPadIJ[0][j];
@@ -1228,11 +973,20 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
     gPad->Modified();
     */
 
+    if (iSimple) {
+      // Simple cluster - skip further passes thru EM-procedure
+      Simple();
+      delete [] coef; delete [] probi; coef = 0; probi = 0;
+      fPixArray->Delete(); 
+      return kTRUE;
+    }
+
     // Calculate position of the center-of-gravity around the maximum pixel
     Double_t xyCOG[2];
     FindCOG(mlem, xyCOG);
 
     if (TMath::Min(pixPtr->Size(0),pixPtr->Size(1)) < 0.07 && pixPtr->Size(0) > pixPtr->Size(1)) break;
+    //if (TMath::Min(pixPtr->Size(0),pixPtr->Size(1)) < 0.007 && pixPtr->Size(0) > pixPtr->Size(1)) break;
     //if (TMath::Min(pixPtr->Size(0),pixPtr->Size(1)) >= 0.07 || pixPtr->Size(0) < pixPtr->Size(1)) {
     // Sort pixels according to the charge
     fPixArray->Sort();
@@ -1332,15 +1086,18 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
   thresh = TMath::Min (thresh,50.);
   Double_t cmax = -1, charge = 0;
   for (Int_t i=0; i<nPix; i++) cmax = TMath::Max (cmax,probi[i]); 
+  //cout << thresh << " " << cmax << " " << cmax*0.9 << endl;
   // Mark pixels which should be removed
   for (Int_t i=0; i<nPix; i++) {
     pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
     charge = pixPtr->Charge();
     if (charge < thresh) pixPtr->SetCharge(-charge);
-    else if (cmax > 1.91) {
-      if (probi[i] < 1.9) pixPtr->SetCharge(-charge);
-    }
-    else if (probi[i] < cmax*0.9) pixPtr->SetCharge(-charge);
+    //else if (cmax > 1.91) {
+    //  if (probi[i] < 1.9) pixPtr->SetCharge(-charge);
+    //}
+    //AZ else if (probi[i] < cmax*0.9) pixPtr->SetCharge(-charge);
+    //18-01-06 else if (probi[i] < cmax*0.8) pixPtr->SetCharge(-charge);
+    //cout << i << " " << pixPtr->Coord(0) << " " << pixPtr->Coord(1) << " " << charge << " " << probi[i] << endl;
   }
   // Move charge of removed pixels to their nearest neighbour (to keep total charge the same)
   Int_t near = 0;
@@ -1350,9 +1107,11 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
     if (charge > 0) continue;
     near = FindNearest(pixPtr);
     pixPtr->SetCharge(0);
+    probi[i] = 0; // make it "invisible"
     pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(near);
-    pixPtr->SetCharge(pixPtr->Charge() - charge);
+    pixPtr->SetCharge(pixPtr->Charge() + (-charge));
   }
+  Mlem(coef,probi,2);
   // Update histogram
   for (Int_t i=0; i<nPix; i++) {
     pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
@@ -1360,15 +1119,8 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
     iy = mlem->GetYaxis()->FindBin(pixPtr->Coord(1));
     mlem->SetBinContent(ix, iy, pixPtr->Charge());
   }
-  if (fDraw) {
-    ((TCanvas*)gROOT->FindObject("c2"))->cd();
-    gPad->SetTheta(55);
-    gPad->SetPhi(30);
-    mlem->Draw("lego1Fb");
-    gPad->Update();
-  }
+  if (fDraw) fDraw->DrawHist("c2", mlem);
 
-  fxyMu[0][6] = fxyMu[1][6] = 9999;
   // Try to split into clusters
   Bool_t ok = kTRUE;
   if (mlem->GetSum() < 1) ok = kFALSE;
@@ -1379,23 +1131,26 @@ Bool_t AliMUONClusterFinderAZ::MainLoop()
 }
 
 //_____________________________________________________________________________
-void AliMUONClusterFinderAZ::Mlem(Double_t *coef, Double_t *probi)
+void AliMUONClusterFinderAZ::Mlem(Double_t *coef, Double_t *probi, Int_t nIter)
 {
   // Use MLEM to find pixel charges
   
   Int_t nPix = fPixArray->GetEntriesFast();
   Int_t npad = fnPads[0] + fnPads[1];
   Double_t *probi1 = new Double_t [nPix];
+  Double_t probMax = 0;
   Int_t indx, indx1;
   AliMUONPixel *pixPtr;
 
-  for (Int_t iter=0; iter<15; iter++) {
+  for (Int_t ipix=0; ipix<nPix; ipix++) if (probi[ipix] > probMax) probMax = probi[ipix];
+  for (Int_t iter=0; iter<nIter; iter++) {
     // Do iterations
     for (Int_t ipix=0; ipix<nPix; ipix++) {
       // Correct each pixel
       if (probi[ipix] < 0.01) continue; // skip "invisible" pixel
       Double_t sum = 0;
-      probi1[ipix] = probi[ipix];
+      //probi1[ipix] = probi[ipix];
+      probi1[ipix] = probMax;
       for (Int_t j=0; j<npad; j++) {
 	if (fPadIJ[1][j] < 0) continue; 
 	Double_t sum1 = 0;
@@ -1406,7 +1161,7 @@ void AliMUONClusterFinderAZ::Mlem(Double_t *coef, Double_t *probi)
 	  pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(i);
 	  sum1 += pixPtr->Charge()*coef[indx1+i];
 	} // for (Int_t i=0;
-	if (fXyq[2][j] > fResponse->MaxAdc()-1 && sum1 > fResponse->MaxAdc()) { probi1[ipix] -= coef[indx]; continue; } // correct for pad charge overflows
+	if (fXyq[2][j] > fgkSaturation-1 && sum1 > fXyq[2][j]) { probi1[ipix] -= coef[indx]; continue; } // correct for pad charge overflows
 	//cout << sum1 << " " << fXyq[2][j] << " " << coef[j*nPix+ipix] << endl;
 	if (coef[indx] > 1.e-6) sum += fXyq[2][j]*coef[indx]/sum1;
       } // for (Int_t j=0;
@@ -1497,7 +1252,7 @@ void AliMUONClusterFinderAZ::FindCOG(TH2D *mlem, Double_t *xyc)
   } // if (nsumx == 1)
 
   xyc[0] = xq/qq; xyc[1] = yq/qq;
-  cout << xyc[0] << " " << xyc[1] << " " << qq << " " << nsum << " " << nsumx << " " << nsumy << endl;
+  if (fDebug) cout << xyc[0] << " " << xyc[1] << " " << qq << " " << nsum << " " << nsumx << " " << nsumy << endl;
   return;
 }
 
@@ -1554,19 +1309,45 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
       used[indx] = 1;
       pix->Add(BinToPix(mlem,j,i));
       AddBin(mlem, i, j, 0, used, pix); // recursive call
+      if (nclust >= 200) AliFatal(" Too many clusters !!!");
       clusters[nclust++] = pix;
-      if (nclust > 200) { cout << " Too many clusters " << endl; ::exit(0); }
     } // for (Int_t j=1; j<=nx; j++) {
   } // for (Int_t i=1; i<=ny;
-  cout << nclust << endl;
+  if (fDebug) cout << nclust << endl;
   delete [] used; used = 0;
   
   // Compute couplings between clusters and clusters to pads
   Int_t npad = fnPads[0] + fnPads[1];
 
+  // Write out some information for algorithm development
+  Int_t cath=0, npadx[2]={0}, npady[2]={0};
+  Double_t xlow[2]={9999,9999}, xhig[2]={-9999,-9999};
+  Double_t ylow[2]={9999,9999}, yhig[2]={-9999,-9999};
+  for (Int_t j=0; j<npad; j++) {
+    if (fXyq[3][j] < 0) continue; // exclude virtual pads
+    cath = fPadIJ[0][j];
+    if (fXyq[0][j] < xlow[cath]-0.001) { 
+      if (fXyq[0][j]+fXyq[3][j] <= xlow[cath] && npadx[cath]) npadx[cath]++;
+      xlow[cath] = fXyq[0][j];
+    }
+    if (fXyq[0][j] > xhig[cath]+0.001) { 
+      if (fXyq[0][j]-fXyq[3][j] >= xhig[cath]) npadx[cath]++; 
+      xhig[cath] = fXyq[0][j]; 
+    }
+    if (fXyq[1][j] < ylow[cath]-0.001) { 
+      if (fXyq[1][j]+fXyq[4][j] <= ylow[cath] && npady[cath]) npady[cath]++;
+      ylow[cath] = fXyq[1][j];
+    }
+    if (fXyq[1][j] > yhig[cath]+0.001) { 
+      if (fXyq[1][j]-fXyq[4][j] >= yhig[cath]) npady[cath]++;
+      yhig[cath] = fXyq[1][j]; 
+    }
+  }
+  //if (lun1) fprintf(lun1," %4d %2d %3d %3d %3d %3d \n",gAlice->GetHeader()->GetEvent(),AliMUONClusterInput::Instance()->Chamber(), npadx[0], npadx[1], npady[0], npady[1]);
+
   // Exclude pads with overflows
   for (Int_t j=0; j<npad; j++) {
-    if (fXyq[2][j] > fResponse->MaxAdc()-1) fPadIJ[1][j] = -9;
+    if (fXyq[2][j] > fgkSaturation-1) fPadIJ[1][j] = -5;
     else fPadIJ[1][j] = 0;
   }
 
@@ -1580,9 +1361,8 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
     for (Int_t i=0; i<npxclu; i++) {
       indx = fPixArray->IndexOf(pix->UncheckedAt(i));
       for (Int_t j=0; j<npad; j++) {
-	// Exclude overflows
-	if (fPadIJ[1][j] < 0) continue;
-	if (coef[j*nPix+indx] < kCouplMin) continue;
+	if (fPadIJ[1][j] < 0 && fPadIJ[1][j] != -5) continue;
+	if (coef[j*nPix+indx] < fgkCouplMin) continue;
 	(*aijclupad)(iclust,j) += coef[j*nPix+indx];
       }
     }
@@ -1594,9 +1374,9 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
     for (Int_t j=0; j<npad; j++) {
       // Exclude overflows
       if (fPadIJ[1][j] < 0) continue;
-      if ((*aijclupad)(iclust,j) < kCouplMin) continue;
+      if ((*aijclupad)(iclust,j) < fgkCouplMin) continue;
       for (Int_t iclust1=iclust+1; iclust1<nclust; iclust1++) {
-	if ((*aijclupad)(iclust1,j) < kCouplMin) continue;
+	if ((*aijclupad)(iclust1,j) < fgkCouplMin) continue;
 	(*aijcluclu)(iclust,iclust1) += 
 	  TMath::Sqrt ((*aijclupad)(iclust,j)*(*aijclupad)(iclust1,j));
       }
@@ -1608,7 +1388,7 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
     }
   }
 
-  if (nclust > 1) aijcluclu->Print();
+  if (fDebug && nclust > 1) aijcluclu->Print();
 
   // Find groups of coupled clusters
   used = new Bool_t[nclust];
@@ -1624,8 +1404,11 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
     nCoupled = 1;
     // Find group of coupled clusters
     AddCluster(igroup, nclust, aijcluclu, used, clustNumb, nCoupled); // recursive
-    cout << " nCoupled: " << nCoupled << endl;
-    for (Int_t i=0; i<nCoupled; i++) cout << clustNumb[i] << " "; cout << endl; 
+    if (fDebug) {
+      cout << " nCoupled: " << nCoupled << endl;
+      for (Int_t i=0; i<nCoupled; i++) cout << clustNumb[i] << " "; cout << endl; 
+    }
+    fnCoupled = nCoupled;
 
     while (nCoupled > 0) {
 
@@ -1642,24 +1425,27 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
 	// Flag clusters for fit
 	nForFit = 0;
 	while (minGroup[nForFit] >= 0 && nForFit < 3) {
-	  cout << clustNumb[minGroup[nForFit]] << " ";
+	  if (fDebug) cout << clustNumb[minGroup[nForFit]] << " ";
 	  clustFit[nForFit] = clustNumb[minGroup[nForFit]];
 	  clustNumb[minGroup[nForFit]] -= 999;
 	  nForFit++;
 	}
-	cout << nForFit << " " << coupl << endl;
+	if (fDebug) cout << nForFit << " " << coupl << endl;
       } // else
 
       // Select pads for fit. 
       if (SelectPad(nCoupled, nForFit, clustNumb, clustFit, aijclupad) < 3 && nCoupled > 1) {
 	// Deselect pads
-	for (Int_t j=0; j<npad; j++) if (TMath::Abs(fPadIJ[1][j]) == 1) fPadIJ[1][j] = 0;
+	for (Int_t j=0; j<npad; j++) {
+	  if (TMath::Abs(fPadIJ[1][j]) == 1) fPadIJ[1][j] = 0;
+	  if (TMath::Abs(fPadIJ[1][j]) == -9) fPadIJ[1][j] = -5;
+	}
 	// Merge the failed cluster candidates (with too few pads to fit) with 
 	// the one with the strongest coupling
 	Merge(nForFit, nCoupled, clustNumb, clustFit, clusters, aijcluclu, aijclupad);
       } else {
 	// Do the fit
-	nfit = Fit(nForFit, clustFit, clusters, parOk);
+	nfit = Fit(0, nForFit, clustFit, clusters, parOk);
       }
 
       // Subtract the fitted charges from pads with strong coupling and/or
@@ -1667,7 +1453,10 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
       UpdatePads(nfit, parOk);
 
       // Mark used pads
-      for (Int_t j=0; j<npad; j++) {if (fPadIJ[1][j] == 1) fPadIJ[1][j] = -1;}
+      for (Int_t j=0; j<npad; j++) {
+	if (fPadIJ[1][j] == 1) fPadIJ[1][j] = -1;
+	if (fPadIJ[1][j] == -9) fPadIJ[1][j] = -5;
+      }
 
       // Sort the clusters (move to the right the used ones)
       Int_t beg = 0, end = nCoupled - 1;
@@ -1701,23 +1490,22 @@ void AliMUONClusterFinderAZ::Split(TH2D *mlem, Double_t *coef)
 	  if (fPadIJ[1][j] != -1) continue;
 	  for (Int_t iclust=0; iclust<nCoupled; iclust++) {
 	    indx = clustNumb[iclust];
-	    if ((*aijclupad)(indx,j) < kCouplMin) continue;
+	    if ((*aijclupad)(indx,j) < fgkCouplMin) continue;
 	    for (Int_t iclust1=iclust+1; iclust1<nCoupled; iclust1++) {
 	      indx1 = clustNumb[iclust1];
-	      if ((*aijclupad)(indx1,j) < kCouplMin) continue;
+	      if ((*aijclupad)(indx1,j) < fgkCouplMin) continue;
 	      // Check this
 	      (*aijcluclu)(indx,indx1) -= 
 		TMath::Sqrt ((*aijclupad)(indx,j)*(*aijclupad)(indx1,j));
 	      (*aijcluclu)(indx1,indx) = (*aijcluclu)(indx,indx1);
 	    }
 	  }
-	  fPadIJ[1][j] = -9;
+	  fPadIJ[1][j] = -8;
 	} // for (Int_t j=0; j<npad;
       } // if (nCoupled > 3)
     } // while (nCoupled > 0)
   } // for (Int_t igroup=0; igroup<nclust;
 
-  //delete aij_clu; aij_clu = 0; delete aijclupad; aijclupad = 0;
   aijcluclu->Delete(); aijclupad->Delete();
   for (Int_t iclust=0; iclust<nclust; iclust++) {
     pix = clusters[iclust]; 
@@ -1765,7 +1553,7 @@ TObject* AliMUONClusterFinderAZ::BinToPix(TH2D *mlem, Int_t jc, Int_t ic)
   Double_t xc = mlem->GetXaxis()->GetBinCenter(jc);
   
   Int_t nPix = fPixArray->GetEntriesFast();
-  AliMUONPixel *pixPtr;
+  AliMUONPixel *pixPtr = NULL;
 
   // Compare pixel and bin positions
   for (Int_t i=0; i<nPix; i++) {
@@ -1773,7 +1561,7 @@ TObject* AliMUONClusterFinderAZ::BinToPix(TH2D *mlem, Int_t jc, Int_t ic)
     if (pixPtr->Charge() < 0.5) continue;
     if (TMath::Abs(pixPtr->Coord(0)-xc)<1.e-4 && TMath::Abs(pixPtr->Coord(1)-yc)<1.e-4) return (TObject*) pixPtr;
   }
-  cout << " Something wrong ??? " << endl;
+  AliError(Form(" Something wrong ??? %f %f ", xc, yc));
   return NULL;
 }
 
@@ -1784,7 +1572,7 @@ void AliMUONClusterFinderAZ::AddCluster(Int_t ic, Int_t nclust, TMatrixD *aijclu
 
   for (Int_t i=0; i<nclust; i++) {
     if (used[i]) continue;
-    if ((*aijcluclu)(i,ic) < kCouplMin) continue;
+    if ((*aijcluclu)(i,ic) < fgkCouplMin) continue;
     used[i] = kTRUE;
     clustNumb[nCoupled++] = i;
     AddCluster(i, nclust, aijcluclu, used, clustNumb, nCoupled);
@@ -1891,16 +1679,16 @@ Int_t AliMUONClusterFinderAZ::SelectPad(Int_t nCoupled, Int_t nForFit, Int_t *cl
   for (Int_t iclust=0; iclust<nForFit; iclust++) {
     indx = clustFit[iclust];
     for (Int_t j=0; j<npad; j++) {
+      if ((*aijclupad)(indx,j) < fgkCouplMin) continue;
+      if (fPadIJ[1][j] == -5) fPadIJ[1][j] = -9; // flag overflow
       if (fPadIJ[1][j] < 0) continue; // exclude overflows and used pads
-      if ((*aijclupad)(indx,j) < kCouplMin) continue;
-      fPadIJ[1][j] = 1; // pad to be used in fit
-      nOK++;
+      if (!fPadIJ[1][j]) { fPadIJ[1][j] = 1; nOK++; } // pad to be used in fit
       if (nCoupled > 3) {
 	// Check other clusters
 	for (Int_t iclust1=0; iclust1<nCoupled; iclust1++) {
 	  indx1 = clustNumb[iclust1];
 	  if (indx1 < 0) continue;
-	  if ((*aijclupad)(indx1,j) < kCouplMin) continue;
+	  if ((*aijclupad)(indx1,j) < fgkCouplMin) continue;
 	  padpix[j] += (*aijclupad)(indx1,j);
 	}
       } // if (nCoupled > 3)
@@ -1910,9 +1698,8 @@ Int_t AliMUONClusterFinderAZ::SelectPad(Int_t nCoupled, Int_t nForFit, Int_t *cl
 
   Double_t aaa = 0;
   for (Int_t j=0; j<npad; j++) {
-    if (padpix[j] < kCouplMin) continue;
-    cout << j << " " << padpix[j] << " "; 
-    cout << fXyq[0][j] << " " << fXyq[1][j] << endl;
+    if (padpix[j] < fgkCouplMin) continue;
+    if (fDebug) cout << j << " " << padpix[j] << " " << fXyq[0][j] << " " << fXyq[1][j] << endl;
     aaa += padpix[j];
     fPadIJ[1][j] = -1; // exclude pads with strong coupling to the other clusters
     nOK--;
@@ -1943,7 +1730,7 @@ void AliMUONClusterFinderAZ::Merge(Int_t nForFit, Int_t nCoupled, Int_t *clustNu
 	imax = indx1;
       }
     } // for (Int_t icl1=0;
-    /*if (couplMax < kCouplMin) {
+    /*if (couplMax < fgkCouplMin) {
       cout << " Oops " << couplMax << endl;
       aijcluclu->Print();
       cout << icl << " " << indx << " " << npxclu << " " << nLinks << endl;
@@ -1954,7 +1741,7 @@ void AliMUONClusterFinderAZ::Merge(Int_t nForFit, Int_t nCoupled, Int_t *clustNu
     npxclu1 = pix1->GetEntriesFast();
     // Add pixels 
     for (Int_t i=0; i<npxclu; i++) { pix1->Add(pix->UncheckedAt(i)); pix->RemoveAt(i); }
-    cout << " New number of pixels: " << npxclu1 << " " << pix1->GetEntriesFast() << endl;
+    if (fDebug) cout << " New number of pixels: " << npxclu1 << " " << pix1->GetEntriesFast() << endl;
     //Add cluster-to-cluster couplings
     //aijcluclu->Print();
     for (Int_t icl1=0; icl1<nCoupled; icl1++) {
@@ -1967,7 +1754,7 @@ void AliMUONClusterFinderAZ::Merge(Int_t nForFit, Int_t nCoupled, Int_t *clustNu
     //aijcluclu->Print();
     //Add cluster-to-pad couplings
     for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
-      if (fPadIJ[1][j] < 0) continue; // exclude overflows and used pads
+      if (fPadIJ[1][j] < 0 && fPadIJ[1][j] != -5) continue; // exclude used pads
       (*aijclupad)(imax,j) += (*aijclupad)(indx,j);
       (*aijclupad)(indx,j) = 0;
     }
@@ -1975,41 +1762,98 @@ void AliMUONClusterFinderAZ::Merge(Int_t nForFit, Int_t nCoupled, Int_t *clustNu
 }
 
 //_____________________________________________________________________________
-Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clusters, Double_t *parOk)
+Int_t AliMUONClusterFinderAZ::Fit(Int_t iSimple, Int_t nfit, Int_t *clustFit, TObjArray **clusters, Double_t *parOk)
 {
   // Find selected clusters to selected pad charges
   
   TH2D *mlem = (TH2D*) gROOT->FindObject("mlem");
-  //Int_t nx = mlem->GetNbinsX();
-  //Int_t ny = mlem->GetNbinsY();
   Double_t xmin = mlem->GetXaxis()->GetXmin() - mlem->GetXaxis()->GetBinWidth(1);
   Double_t xmax = mlem->GetXaxis()->GetXmax() + mlem->GetXaxis()->GetBinWidth(1);
   Double_t ymin = mlem->GetYaxis()->GetXmin() - mlem->GetYaxis()->GetBinWidth(1);
   Double_t ymax = mlem->GetYaxis()->GetXmax() + mlem->GetYaxis()->GetBinWidth(1);
-  //Double_t qmin = 0, qmax = 1;
-  Double_t step[3]={0.01,0.002,0.02};
-
-  Double_t cont, cmax = 0, xseed = 0, yseed = 0, errOk[8];
-  TObjArray *pix;
-  Int_t npxclu;
+  Double_t step[3]={0.01,0.002,0.02}, xPad = 0, yPad = 99999;
 
-  // Number of pads to use
-  Int_t npads = 0;
-  for (Int_t i=0; i<fnPads[0]+fnPads[1]; i++) {if (fPadIJ[1][i] == 1) npads++;}
-  for (Int_t i=0; i<nfit; i++) {cout << i+1 << " " << clustFit[i] << " ";}
-  cout << nfit << endl;
-  cout << " Number of pads to fit: " << npads << endl;
+  // Number of pads to use and number of virtual pads
+  Int_t npads = 0, nVirtual = 0, nfit0 = nfit;
+  for (Int_t i=0; i<fnPads[0]+fnPads[1]; i++) {
+    if (fXyq[3][i] < 0) nVirtual++;
+    if (fPadIJ[1][i] != 1) continue;
+    if (fXyq[3][i] > 0) {
+      npads++;
+      if (yPad > 9999) { 
+	xPad = fXyq[0][i]; 
+	yPad = fXyq[1][i]; 
+      } else {
+	if (fXyq[4][i] < fXyq[3][i]) yPad = fXyq[1][i]; 
+	else xPad = fXyq[0][i]; 
+      }
+    }
+  }
+  if (fDebug) {
+    for (Int_t i=0; i<nfit; i++) {cout << i+1 << " " << clustFit[i] << " ";}
+    cout << nfit << endl;
+    cout << " Number of pads to fit: " << npads << endl;
+  }
   fNpar = 0;
   fQtot = 0;
   if (npads < 2) return 0; 
+  
+  Int_t digit = 0;
+  AliMUONDigit *mdig = 0;
+  Int_t tracks[3] = {-1, -1, -1};
+  for (Int_t cath=0; cath<2; cath++) {  
+    for (Int_t i=0; i<fnPads[0]+fnPads[1]; i++) {
+      if (fPadIJ[0][i] != cath) continue;
+      if (fPadIJ[1][i] != 1) continue;
+      if (fXyq[3][i] < 0) continue; // exclude virtual pads
+      digit = TMath::Nint (fXyq[5][i]);
+      if (digit >= 0) mdig = fInput->Digit(cath,digit);
+      else mdig = fInput->Digit(TMath::Even(cath),-digit-1);
+      //if (!mdig) mdig = fInput->Digit(TMath::Even(cath),digit);
+      if (!mdig) continue; // protection for cluster display
+      if (mdig->Hit() >= 0) {
+	if (tracks[0] < 0) {
+	  tracks[0] = mdig->Hit();
+	  tracks[1] = mdig->Track(0);
+	} else if (mdig->Track(0) < tracks[1]) {
+	  tracks[0] = mdig->Hit();
+	  tracks[1] = mdig->Track(0);
+	}
+      }
+      if (mdig->Track(1) >= 0 && mdig->Track(1) != tracks[1]) {
+	if (tracks[2] < 0) tracks[2] = mdig->Track(1);
+	else tracks[2] = TMath::Min (tracks[2], mdig->Track(1));
+      }
+      //if (!mdig) break;
+      //cout << mdig->Hit() << " " << mdig->Track(0) << " " << mdig->Track(1) <<endl;
+    } // for (Int_t i=0;
+  } // for (Int_t cath=0;
+  //cout << tracks[0] << " " << tracks[1] << " " << tracks[2] <<endl;
+  
+  // Get number of pads in X and Y 
+  Int_t nInX = 0, nInY;
+  PadsInXandY(nInX, nInY);
+  //cout << " nInX and Y: " << nInX << " " << nInY << endl;
+
+  Int_t nfitMax = 3; 
+  nfitMax = TMath::Min (nfitMax, (npads + 1) / 3);
+  if (nfitMax > 1) {
+    if (nInX < 3 && nInY < 3 || nInX == 3 && nInY < 3 || nInX < 3 && nInY == 3) nfitMax = 1; // not enough pads in each direction
+  }
+  if (nfit > nfitMax) nfit = nfitMax;
 
   // Take cluster maxima as fitting seeds
+  TObjArray *pix;
   AliMUONPixel *pixPtr;
-  Double_t xyseed[3][2], qseed[3];
-  for (Int_t ifit=1; ifit<=nfit; ifit++) {
+  Int_t npxclu;
+  Double_t cont, cmax = 0, xseed = 0, yseed = 0, errOk[8], qq = 0;
+  Double_t xyseed[3][2], qseed[3], xyCand[3][2] = {{0},{0}}, sigCand[3][2] = {{0},{0}};
+
+  for (Int_t ifit=1; ifit<=nfit0; ifit++) {
     cmax = 0;
     pix = clusters[clustFit[ifit-1]];
     npxclu = pix->GetEntriesFast();
+    //qq = 0;
     for (Int_t clu=0; clu<npxclu; clu++) {
       pixPtr = (AliMUONPixel*) pix->UncheckedAt(clu);
       cont = pixPtr->Charge();
@@ -2019,33 +1863,96 @@ Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clust
 	xseed = pixPtr->Coord(0);
 	yseed = pixPtr->Coord(1);
       }
+      qq += cont;
+      /*
+      xyCand[ifit-1][0] += pixPtr->Coord(0) * cont;
+      xyCand[ifit-1][1] += pixPtr->Coord(1) * cont;
+      sigCand[ifit-1][0] += pixPtr->Coord(0) * pixPtr->Coord(0) * cont;
+      sigCand[ifit-1][1] += pixPtr->Coord(1) * pixPtr->Coord(1) * cont;
+      */
+      xyCand[0][0] += pixPtr->Coord(0) * cont;
+      xyCand[0][1] += pixPtr->Coord(1) * cont;
+      sigCand[0][0] += pixPtr->Coord(0) * pixPtr->Coord(0) * cont;
+      sigCand[0][1] += pixPtr->Coord(1) * pixPtr->Coord(1) * cont;
     }
     xyseed[ifit-1][0] = xseed;
     xyseed[ifit-1][1] = yseed;
     qseed[ifit-1] = cmax;
+    /*
+    xyCand[ifit-1][0] /= qq; // <x>
+    xyCand[ifit-1][1] /= qq; // <y>
+    sigCand[ifit-1][0] = sigCand[ifit-1][0]/qq - xyCand[ifit-1][0]*xyCand[ifit-1][0]; // <x^2> - <x>^2
+    sigCand[ifit-1][0] = sigCand[ifit-1][0] > 0 ? TMath::Sqrt (sigCand[ifit-1][0]) : 0;
+    sigCand[ifit-1][1] = sigCand[ifit-1][1]/qq - xyCand[ifit-1][1]*xyCand[ifit-1][1]; // <y^2> - <y>^2
+    sigCand[ifit-1][1] = sigCand[ifit-1][1] > 0 ? TMath::Sqrt (sigCand[ifit-1][1]) : 0;
+    cout << xyCand[ifit-1][0] << " " << xyCand[ifit-1][1] << " " << sigCand[ifit-1][0] << " " << sigCand[ifit-1][1] << endl;
+    */
   } // for (Int_t ifit=1;
 
-  Int_t nDof, maxSeed[3];
+  xyCand[0][0] /= qq; // <x>
+  xyCand[0][1] /= qq; // <y>
+  sigCand[0][0] = sigCand[0][0]/qq - xyCand[0][0]*xyCand[0][0]; // <x^2> - <x>^2
+  sigCand[0][0] = sigCand[0][0] > 0 ? TMath::Sqrt (sigCand[0][0]) : 0;
+  sigCand[0][1] = sigCand[0][1]/qq - xyCand[0][1]*xyCand[0][1]; // <y^2> - <y>^2
+  sigCand[0][1] = sigCand[0][1] > 0 ? TMath::Sqrt (sigCand[0][1]) : 0;
+  if (fDebug) cout << xyCand[0][0] << " " << xyCand[0][1] << " " << sigCand[0][0] << " " << sigCand[0][1] << endl;
+
+  Int_t nDof, maxSeed[3], nMax = 0;
   Double_t fmin, chi2o = 9999, chi2n;
 
-  // Try to fit with one-track hypothesis, then 2-track. If chi2/dof is 
-  // lower, try 3-track (if number of pads is sufficient).
-  
-  TMath::Sort(nfit, qseed, maxSeed, kTRUE); // in decreasing order
-  nfit = TMath::Min (nfit, (npads + 1) / 3);
+  TMath::Sort(nfit0, qseed, maxSeed, kTRUE); // in decreasing order
+  /*
+  Int_t itmp[100], localMax[100];
+  Double_t maxVal[100];
+  if (!iSimple && nfit < nfitMax) {
+    // Try to split pixel cluster according to local maxima
+    Int_t nfit1 = nfit;
+    for (Int_t iclus = 0; iclus < nfit1; iclus++) {
+      nMax = FindLocalMaxima (clusters[clustFit[maxSeed[iclus]]], localMax, maxVal);
+      TH2D *hist = (TH2D*) gROOT->FindObject("anode1");
+      if (nMax == 1) { hist->Delete(); continue; }
+      // Add extra fitting seeds from local maxima
+      Int_t ixseed = hist->GetXaxis()->FindBin(xyseed[maxSeed[iclus]][0]);
+      Int_t iyseed = hist->GetYaxis()->FindBin(xyseed[maxSeed[iclus]][1]);
+      Int_t nx = hist->GetNbinsX();
+      TMath::Sort(nMax, maxVal, itmp, kTRUE); // in decreasing order
+      for (Int_t j = 0; j < nMax; j++) {
+	Int_t iyc = localMax[itmp[j]] / nx + 1;
+	Int_t ixc = localMax[itmp[j]] % nx + 1;
+	if (ixc == ixseed && iyc == iyseed) continue; // local max already taken for seeding
+	xyseed[nfit][0] = hist->GetXaxis()->GetBinCenter(ixc);
+	xyseed[nfit][1] = hist->GetYaxis()->GetBinCenter(iyc);
+	qseed[nfit] = maxVal[itmp[j]];
+	maxSeed[nfit] = nfit++;
+	if (nfit >= nfitMax) break;
+      }
+      hist->Delete();
+      if (nfit >= nfitMax) break;
+    } // for (Int_t iclus = 0;
+    //nfit0 = nfit;
+    //TMath::Sort(nfit0, qseed, maxSeed, kTRUE); // in decreasing order
+  } //if (!iSimple && nfit < nfitMax)
+  */
 
-  Double_t *gin = 0, func0, func1, param[8], param0[2][8], deriv[2][8], step0[8];
+  Double_t *gin = 0, func0, func1, param[8], step0[8];
+  Double_t param0[2][8]={{0},{0}}, deriv[2][8]={{0},{0}}; 
   Double_t shift[8], stepMax, derMax, parmin[8], parmax[8], func2[2], shift0;
   Double_t delta[8], scMax, dder[8], estim, shiftSave = 0;
   Int_t min, max, nCall = 0, memory[8] = {0}, nLoop, idMax = 0, iestMax = 0, nFail;
+  Double_t rad, dist[3] = {0};
 
+  // Try to fit with one-track hypothesis, then 2-track. If chi2/dof is 
+  // lower, try 3-track (if number of pads is sufficient).
   for (Int_t iseed=0; iseed<nfit; iseed++) {
 
+    if (iseed) { for (Int_t j=0; j<fNpar; j++) param[j] = parOk[j]; } // for bounded params
     for (Int_t j=0; j<3; j++) step0[fNpar+j] = shift[fNpar+j] = step[j];
-    param[fNpar] = xyseed[maxSeed[iseed]][0];
+    if (nfit == 1) param[fNpar] = xyCand[0][0]; // take COG
+    else param[fNpar] = xyseed[maxSeed[iseed]][0];
     parmin[fNpar] = xmin; 
     parmax[fNpar++] = xmax; 
-    param[fNpar] = xyseed[maxSeed[iseed]][1];
+    if (nfit == 1) param[fNpar] = xyCand[0][1]; // take COG
+    else param[fNpar] = xyseed[maxSeed[iseed]][1];
     parmin[fNpar] = ymin; 
     parmax[fNpar++] = ymax; 
     if (fNpar > 2) {
@@ -2053,13 +1960,14 @@ Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clust
       parmin[fNpar] = 0; 
       parmax[fNpar++] = 1; 
     }
+    if (iseed) { for (Int_t j=0; j<fNpar; j++) param0[1][j] = 0; }
 
     // Try new algorithm
     min = nLoop = 1; stepMax = func2[1] = derMax = 999999; nFail = 0;
 
     while (1) {
       max = !min;
-      fcn1(fNpar, gin, func0, param, 1); nCall++;
+      Fcn1(fNpar, gin, func0, param, 1); nCall++;
       //cout << " Func: " << func0 << endl;
 
       func2[max] = func0;
@@ -2068,14 +1976,14 @@ Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clust
 	delta[j] = step0[j];
 	param[j] += delta[j] / 10;
 	if (j > 0) param[j-1] -= delta[j-1] / 10;
-	fcn1(fNpar, gin, func1, param, 1); nCall++;
+	Fcn1(fNpar, gin, func1, param, 1); nCall++;
 	deriv[max][j] = (func1 - func0) / delta[j] * 10; // first derivative
 	//cout << j << " " << deriv[max][j] << endl;
 	dder[j] = param0[0][j] != param0[1][j] ? (deriv[0][j] - deriv[1][j]) / 
-	                                         (param0[0][j] - param0[1][j]) : 0; // second derivative
+	  (param0[0][j] - param0[1][j]) : 0; // second derivative
       }
       param[fNpar-1] -= delta[fNpar-1] / 10;
-      if (nCall > 2000) ::exit(0);
+      if (nCall > 2000) break;
 
       min = func2[0] < func2[1] ? 0 : 1;
       nFail = min == max ? 0 : nFail + 1;
@@ -2087,14 +1995,15 @@ Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clust
 	if (nLoop == 1) shift[j] = TMath::Sign (step0[j], -deriv[max][j]); // first step
 	else if (TMath::Abs(deriv[0][j]) < 1.e-3 && TMath::Abs(deriv[1][j]) < 1.e-3) shift[j] = 0;
 	else if (deriv[min][j]*deriv[!min][j] > 0 && TMath::Abs(deriv[min][j]) > TMath::Abs(deriv[!min][j])
-	      || TMath::Abs(deriv[0][j]-deriv[1][j]) < 1.e-3) {
+		 //|| TMath::Abs(deriv[0][j]-deriv[1][j]) < 1.e-3) {
+	  || TMath::Abs(deriv[0][j]-deriv[1][j]) < 1.e-3 || TMath::Abs(dder[j]) < 1.e-6) {
 	  shift[j] = -TMath::Sign (shift[j], (func2[0]-func2[1]) * (param0[0][j]-param0[1][j]));
 	  if (min == max) { 
 	    if (memory[j] > 1) { shift[j] *= 2; } //cout << " Memory " << memory[j] << " " << shift[j] << endl; }
 	    memory[j]++;
 	  }
 	} else {
-	  shift[j] = -deriv[min][j] / dder[j];
+	  shift[j] = dder[j] != 0 ? -deriv[min][j] / dder[j] : 0;
 	  memory[j] = 0;
 	}
 	if (TMath::Abs(shift[j])/step0[j] > estim) { 
@@ -2124,7 +2033,14 @@ Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clust
 	    shift[j] = TMath::Sign (shift0*scMax, shift[j]);
 	}
 	param[j] += shift[j]; 
-	  
+	//AZ Check parameter limits 27-12-2004
+	if (param[j] < parmin[j]) { 
+	  shift[j] = parmin[j] - param[j]; 
+	  param[j] = parmin[j]; 
+	} else if (param[j] > parmax[j]) {
+          shift[j] = parmax[j] - param[j];
+          param[j] = parmax[j];
+	}
 	//cout << " xxx " << j << " " << shift[j] << " " << param[j] << endl;
 	stepMax = TMath::Max (stepMax, TMath::Abs(shift[j]/step0[j]));
 	if (TMath::Abs(deriv[min][j]) > derMax) {
@@ -2133,7 +2049,7 @@ Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clust
 	}
       } // for (Int_t j=0; j<fNpar;
       //cout << max << " " << func2[min] << " " << derMax << " " << stepMax << " " << estim << " " << iestMax << " " << nCall << endl;
-      if (estim < 1 && derMax < 2 || nLoop > 100) break; // minimum was found
+      if (estim < 1 && derMax < 2 || nLoop > 150) break; // minimum was found
 
       nLoop++;
       // Check for small step
@@ -2158,91 +2074,155 @@ Int_t AliMUONClusterFinderAZ::Fit(Int_t nfit, Int_t *clustFit, TObjArray **clust
     } // while (1)
     fmin = func2[min];
 
-    nDof = npads - fNpar;
-    chi2n = nDof ? fmin/nDof : 0;
+    nDof = npads - fNpar + nVirtual;
+    if (!nDof) nDof++;
+    chi2n = fmin / nDof;
+    if (fDebug) cout << " Chi2 " << chi2n << " " << fNpar << endl;
 
     if (chi2n*1.2+1.e-6 > chi2o ) { fNpar -= 3; break; }
+
     // Save parameters and errors
+
+    if (nInX == 1) {
+      // One pad per direction 
+      for (Int_t i=0; i<fNpar; i++) if (i == 0 || i == 2 || i == 5) param0[min][i] = xPad;
+    }
+    if (nInY == 1) {
+      // One pad per direction 
+      for (Int_t i=0; i<fNpar; i++) if (i == 1 || i == 3 || i == 6) param0[min][i] = yPad;
+    }
+
+    /*
+    if (iseed > 0) {
+      // Find distance to the nearest neighbour
+      dist[0] = dist[1] = TMath::Sqrt ((param0[min][0]-param0[min][2])*
+				       (param0[min][0]-param0[min][2])
+				      +(param0[min][1]-param0[min][3])*
+				       (param0[min][1]-param0[min][3]));
+      if (iseed > 1) {
+	dist[2] = TMath::Sqrt ((param0[min][0]-param0[min][5])*
+			       (param0[min][0]-param0[min][5])
+			      +(param0[min][1]-param0[min][6])*
+			       (param0[min][1]-param0[min][6]));
+	rad = TMath::Sqrt ((param0[min][2]-param0[min][5])*
+			   (param0[min][2]-param0[min][5])
+			  +(param0[min][3]-param0[min][6])*
+			   (param0[min][3]-param0[min][6]));
+	if (dist[2] < dist[0]) dist[0] = dist[2];
+	if (rad < dist[1]) dist[1] = rad;
+	if (rad < dist[2]) dist[2] = rad;
+      }
+      cout << dist[0] << " " << dist[1] << " " << dist[2] << endl;
+      if (dist[TMath::LocMin(iseed+1,dist)] < 1.) { fNpar -= 3; break; }
+    }
+    */
+
     for (Int_t i=0; i<fNpar; i++) {
       parOk[i] = param0[min][i];
-      errOk[i] = fmin;
+      //errOk[i] = fmin;
+      errOk[i] = chi2n;
+      // Bounded params
+      parOk[i] = TMath::Max (parOk[i], parmin[i]);
+      parOk[i] = TMath::Min (parOk[i], parmax[i]);
     }
 
-    cout << chi2o << " " << chi2n << endl;
     chi2o = chi2n;
     if (fmin < 0.1) break; // !!!???
   } // for (Int_t iseed=0; 
 
-  for (Int_t i=0; i<fNpar; i++) {
-    if (i == 4 || i == 7) continue;
-    cout << parOk[i] << " " << errOk[i] << endl;
+  if (fDebug) {
+    for (Int_t i=0; i<fNpar; i++) {
+      if (i == 4 || i == 7) {
+	if (i == 7 || i == 4 && fNpar < 7) cout << parOk[i] << endl;
+	else cout << parOk[i] * (1-parOk[7]) << endl;
+	continue;
+      }
+      cout << parOk[i] << " " << errOk[i] << endl;
+    }
   }
   nfit = (fNpar + 1) / 3;
-  Double_t rad;
-  Int_t indx, imax;
-  if (fReco) {
-    for (Int_t j=0; j<nfit; j++) {
-      indx = j<2 ? j*2 : j*2+1;  
-      AddRawCluster (parOk[indx], parOk[indx+1], errOk[indx]);
+  dist[0] = dist[1] = dist[2] = 0;
+
+  if (nfit > 1) {
+    // Find distance to the nearest neighbour
+    dist[0] = dist[1] = TMath::Sqrt ((parOk[0]-parOk[2])*
+				     (parOk[0]-parOk[2])
+				    +(parOk[1]-parOk[3])*
+				     (parOk[1]-parOk[3]));
+    if (nfit > 2) {
+      dist[2] = TMath::Sqrt ((parOk[0]-parOk[5])*
+			     (parOk[0]-parOk[5])
+			    +(parOk[1]-parOk[6])*
+			     (parOk[1]-parOk[6]));
+      rad = TMath::Sqrt ((parOk[2]-parOk[5])*
+			 (parOk[2]-parOk[5])
+			+(parOk[3]-parOk[6])*
+			 (parOk[3]-parOk[6]));
+      if (dist[2] < dist[0]) dist[0] = dist[2];
+      if (rad < dist[1]) dist[1] = rad;
+      if (rad < dist[2]) dist[2] = rad;
     }
-    return nfit;
-  } 
-  for (Int_t i=0; i<fnMu; i++) {
-    cmax = fxyMu[i][6];
-    for (Int_t j=0; j<nfit; j++) {
-      indx = j<2 ? j*2 : j*2+1;  
-      rad = (fxyMu[i][0]-parOk[indx])*(fxyMu[i][0]-parOk[indx]) +
-            (fxyMu[i][1]-parOk[indx+1])*(fxyMu[i][1]-parOk[indx+1]);
-      if (rad < cmax) {
-	cmax = rad; 
-	imax = indx;
-	fxyMu[i][6] = cmax;
-	fxyMu[i][2] = parOk[imax] - fxyMu[i][0];
-	fxyMu[i][4] = parOk[imax+1] - fxyMu[i][1];
-	fxyMu[i][3] = errOk[imax];
-	fxyMu[i][5] = errOk[imax+1];
-      }
-    }      
   }
+
+  Int_t indx;
+  fnPads[1] -= nVirtual;
+  if (!fDraw) {
+    Double_t coef = 0;
+    if (iSimple) fnCoupled = 0;
+    //for (Int_t j=0; j<nfit; j++) {
+    for (Int_t j=nfit-1; j>=0; j--) {
+      indx = j<2 ? j*2 : j*2+1;  
+      if (nfit == 1) coef = 1;
+      else coef = j==nfit-1 ? parOk[indx+2] : 1-coef;
+      coef = TMath::Max (coef, 0.);
+      if (nfit == 3 && j < 2) coef = j==1 ? coef*parOk[indx+2] : coef - parOk[7];
+      coef = TMath::Max (coef, 0.);
+      AddRawCluster (parOk[indx], parOk[indx+1], coef*fQtot, errOk[indx], nfit0+10*nfit+100*nMax+10000*fnCoupled, tracks,
+		     //sigCand[maxSeed[j]][0], sigCand[maxSeed[j]][1]);
+		     //sigCand[0][0], sigCand[0][1], dist[j]);
+		     sigCand[0][0], sigCand[0][1], dist[TMath::LocMin(nfit,dist)]);
+    }
+  } else fDraw->FillMuon(nfit, parOk, errOk);
   return nfit;
 }  
 
 //_____________________________________________________________________________
-void AliMUONClusterFinderAZ::fcn1(Int_t & /*npar*/, Double_t * /*gin*/, Double_t &f, Double_t *par, Int_t /*iflag*/)
+void AliMUONClusterFinderAZ::Fcn1(Int_t & /*npar*/, Double_t * /*gin*/, Double_t &f, Double_t *par, Int_t /*iflag*/)
 {
   // Fit for one track
-  AliMUONClusterFinderAZ& c = *(AliMUONClusterFinderAZ::fgClusterFinder);    
+  //AZ for Muinuit AliMUONClusterFinderAZ& c = *(AliMUONClusterFinderAZ::fgClusterFinder);    
+  AliMUONClusterFinderAZ& c = *this; //AZ
   
   Int_t cath, ix, iy, indx, npads=0;
-  Double_t charge, delta, coef=0, chi2=0;
+  Double_t charge, delta, coef=0, chi2=0, qTot = 0;
   for (Int_t j=0; j<c.fnPads[0]+c.fnPads[1]; j++) {
     if (c.fPadIJ[1][j] != 1) continue;
     cath = c.fPadIJ[0][j];
-    npads++;
-    c.fSegmentation[cath]->GetPadI(c.fXyq[0][j],c.fXyq[1][j],c.fZpad,ix,iy);
-    c.fSegmentation[cath]->SetPad(ix,iy);
+    if (c.fXyq[3][j] > 0) npads++; // exclude virtual pads
+    qTot += c.fXyq[2][j];
+    ix = c.fPadIJ[2][j];
+    iy = c.fPadIJ[3][j];
+    c.fSegmentation[cath]->SetPad(ix, iy);
     charge = 0;
     for (Int_t i=c.fNpar/3; i>=0; i--) { // sum over tracks
       indx = i<2 ? 2*i : 2*i+1;
-      c.fSegmentation[cath]->SetHit(par[indx],par[indx+1],c.fZpad);
-      //charge += c.fResponse->IntXY(c.fSegmentation[cath])*par[icl*3+2];
+      c.fSegmentation[cath]->SetHit(par[indx], par[indx+1], c.fZpad);
       if (c.fNpar == 2) coef = 1;
       else coef = i==c.fNpar/3 ? par[indx+2] : 1-coef;
-      //coef = TMath::Max (coef, 0.);
+      coef = TMath::Max (coef, 0.);
       if (c.fNpar == 8 && i < 2) coef = i==1 ? coef*par[indx+2] : coef - par[7];
-      //coef = TMath::Max (coef, 0.);
-      charge += c.fResponse->IntXY(c.fSegmentation[cath])*coef;
+      coef = TMath::Max (coef, 0.);
+      charge += c.fInput->Mathieson()->IntXY(fInput->DetElemId(), c.fInput->Segmentation2(cath))*coef;
     }
     charge *= c.fQtot;
-    //if (c.fXyq[2][j] > c.fResponse->MaxAdc()-1 && charge > 
-    //	c.fResponse->MaxAdc()) charge = c.fResponse->MaxAdc(); 
     delta = charge - c.fXyq[2][j];
-    delta /= TMath::Sqrt ((Double_t)c.fXyq[2][j]);
-    //chi2 += TMath::Abs(delta);
-    chi2 += delta*delta;
+    delta *= delta;
+    delta /= c.fXyq[2][j];
+    //if (cath) delta /= 5; // just for test
+    chi2 += delta;
   } // for (Int_t j=0;
   f = chi2; 
-  Double_t qAver = c.fQtot/npads; //(c.fnPads[0]+c.fnPads[1]);
+  Double_t qAver = qTot/npads; //(c.fnPads[0]+c.fnPads[1]);
   f = chi2/qAver;
 }
 
@@ -2257,26 +2237,29 @@ void AliMUONClusterFinderAZ::UpdatePads(Int_t /*nfit*/, Double_t *par)
     if (fPadIJ[1][j] != -1) continue;
     if (fNpar != 0) {
       cath = fPadIJ[0][j];
-      fSegmentation[cath]->GetPadI(fXyq[0][j],fXyq[1][j],fZpad,ix,iy);
-      fSegmentation[cath]->SetPad(ix,iy);
+      ix = fPadIJ[2][j];
+      iy = fPadIJ[3][j];
+      fSegmentation[cath]->SetPad(ix, iy);
       charge = 0;
       for (Int_t i=fNpar/3; i>=0; i--) { // sum over tracks
 	indx = i<2 ? 2*i : 2*i+1;
-	fSegmentation[cath]->SetHit(par[indx],par[indx+1],fZpad);
+	fSegmentation[cath]->SetHit(par[indx], par[indx+1], fZpad);
 	if (fNpar == 2) coef = 1;
 	else coef = i==fNpar/3 ? par[indx+2] : 1-coef;
+	coef = TMath::Max (coef, 0.);
 	if (fNpar == 8 && i < 2) coef = i==1 ? coef*par[indx+2] : coef - par[7];
-	charge += fResponse->IntXY(fSegmentation[cath])*coef;
+	coef = TMath::Max (coef, 0.);
+	charge += fInput->Mathieson()->IntXY(fInput->DetElemId(),fInput->Segmentation2(cath))*coef;
       }
       charge *= fQtot;
       fXyq[2][j] -= charge;
     } // if (fNpar != 0)
-    if (fXyq[2][j] > fResponse->ZeroSuppression()) fPadIJ[1][j] = 0; // return pad for further using
+    if (fXyq[2][j] > fgkZeroSuppression) fPadIJ[1][j] = 0; // return pad for further using
   } // for (Int_t j=0;
 }  
 
 //_____________________________________________________________________________
-Bool_t AliMUONClusterFinderAZ::TestTrack(Int_t /*t*/) {
+Bool_t AliMUONClusterFinderAZ::TestTrack(Int_t /*t*/) const {
 // Test if track was user selected
   return kTRUE;
   /*
@@ -2291,55 +2274,72 @@ Bool_t AliMUONClusterFinderAZ::TestTrack(Int_t /*t*/) {
 }
 
 //_____________________________________________________________________________
-void AliMUONClusterFinderAZ::AddRawCluster(Double_t x, Double_t y, Double_t fmin)
+void AliMUONClusterFinderAZ::AddRawCluster(Double_t x, Double_t y, Double_t qTot, Double_t fmin, Int_t nfit, Int_t *tracks, Double_t /*sigx*/, Double_t /*sigy*/, Double_t /*dist*/)
 {
   //
   // Add a raw cluster copy to the list
   //
+  if (qTot <= 0.501) return; 
   AliMUONRawCluster cnew;
-  AliMUON *pMUON=(AliMUON*)gAlice->GetModule("MUON");
-  //pMUON->AddRawCluster(fInput->Chamber(),c); 
 
-  Int_t cath;    
+  Int_t cath, npads[2] = {0}, nover[2] = {0};
+  for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
+    cath = fPadIJ[0][j];
+    // There was an overflow
+    if (fPadIJ[1][j] == -9) nover[cath]++;
+    if (fPadIJ[1][j] != 1 && fPadIJ[1][j] != -9) continue;
+    cnew.SetMultiplicity(cath,cnew.GetMultiplicity(cath)+1);
+    if (fXyq[2][j] > cnew.GetPeakSignal(cath)) cnew.SetPeakSignal(cath,TMath::Nint (fXyq[2][j]));
+    //cnew.SetCharge(cath,cnew.GetCharge(cath) + TMath::Nint (fXyq[2][j]));
+    cnew.SetContrib(npads[cath],cath,fXyq[2][j]);
+    cnew.SetIndex(npads[cath],cath,TMath::Nint (fXyq[5][j]));
+    cnew.SetDetElemId(fInput->DetElemId());
+    npads[cath]++;
+  }
+
+  cnew.SetClusterType(nover[0] + nover[1] * 100);
+  for (Int_t j=0; j<3; j++) cnew.SetTrack(j,tracks[j]);
+
+  Double_t xg, yg, zg;
   for (cath=0; cath<2; cath++) {
-    cnew.SetX(cath, x);
-    cnew.SetY(cath, y);
-    cnew.SetZ(cath, fZpad);
-    cnew.SetCharge(cath, 100);
-    cnew.SetPeakSignal(cath,20);
-    cnew.SetMultiplicity(cath, 5);
-    cnew.SetNcluster(cath, 1);
-    cnew.SetChi2(cath, fmin); //0.1;
-    /*
-    cnew.fMultiplicity[cath]=c->fMultiplicity[cath];
-    for (i=0; i<fMul[cath]; i++) {
-      cnew.fIndexMap[i][cath]=c->fIndexMap[i][cath];
-      fSeg[cath]->SetPad(fIx[i][cath], fIy[i][cath]);
-    }
-    fprintf(stderr,"\nRawCluster %d cath %d\n",ico,cath);
-    fprintf(stderr,"mult_av %d\n",c->fMultiplicity[cath]);
-    FillCluster(&cnew,cath);
-    */
+    // Perform local-to-global transformation
+    fInput->Segmentation2(cath)->GetTransformer()->Local2Global(fInput->DetElemId(), x, y, fZpad, xg, yg, zg);
+    cnew.SetX(cath, xg);
+    cnew.SetY(cath, yg);
+    cnew.SetZ(cath, zg);
+    cnew.SetCharge(cath, TMath::Nint(qTot));
+    //cnew.SetPeakSignal(cath,20);
+    //cnew.SetMultiplicity(cath, 5);
+    cnew.SetNcluster(cath, nfit);
+    cnew.SetChi2(cath, fmin); //0.;1
   } 
+  // Evaluate measurement errors
+  //AZ Errors(&cnew);
+
+  cnew.SetGhost(nfit); //cnew.SetX(1,sigx); cnew.SetY(1,sigy); cnew.SetZ(1,dist);
   //cnew.fClusterType=cnew.PhysicsContribution();
-  pMUON->GetMUONData()->AddRawCluster(AliMUONClusterInput::Instance()->Chamber(),cnew); 
+  new((*fRawClusters)[fNRawClusters++]) AliMUONRawCluster(cnew); 
+  if (fDebug) cout << fNRawClusters << " " << fInput->Chamber() << endl;
   //fNPeaks++;
 }
 
 //_____________________________________________________________________________
-Int_t AliMUONClusterFinderAZ::FindLocalMaxima(Int_t *localMax, Double_t *maxVal)
+Int_t AliMUONClusterFinderAZ::FindLocalMaxima(TObjArray *pixArray, Int_t *localMax, Double_t *maxVal)
 {
   // Find local maxima in pixel space for large preclusters in order to
   // try to split them into smaller pieces (to speed up the MLEM procedure)
+  // or to find additional fitting seeds if clusters were not completely resolved  
 
-  TH2D *hist = (TH2D*) gROOT->FindObject("anode");
-  if (hist) hist->Delete();
+  TH2D *hist = NULL;
+  //if (pixArray == fPixArray) hist = (TH2D*) gROOT->FindObject("anode");
+  //else { hist = (TH2D*) gROOT->FindObject("anode1"); cout << hist << endl; }
+  //if (hist) hist->Delete();
 
   Double_t xylim[4] = {999, 999, 999, 999};
-  Int_t nPix = fPixArray->GetEntriesFast();
+  Int_t nPix = pixArray->GetEntriesFast();
   AliMUONPixel *pixPtr = 0;
   for (Int_t ipix=0; ipix<nPix; ipix++) {
-    pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(ipix);
+    pixPtr = (AliMUONPixel*) pixArray->UncheckedAt(ipix);
     for (Int_t i=0; i<4; i++) 
          xylim[i] = TMath::Min (xylim[i], (i%2 ? -1 : 1)*pixPtr->Coord(i/2));
   }
@@ -2347,20 +2347,13 @@ Int_t AliMUONClusterFinderAZ::FindLocalMaxima(Int_t *localMax, Double_t *maxVal)
 
   Int_t nx = TMath::Nint ((-xylim[1]-xylim[0])/pixPtr->Size(0)/2);
   Int_t ny = TMath::Nint ((-xylim[3]-xylim[2])/pixPtr->Size(1)/2);
-  hist = new TH2D("anode","anode",nx,xylim[0],-xylim[1],ny,xylim[2],-xylim[3]);
+  if (pixArray == fPixArray) hist = new TH2D("anode","anode",nx,xylim[0],-xylim[1],ny,xylim[2],-xylim[3]);
+  else hist = new TH2D("anode1","anode1",nx,xylim[0],-xylim[1],ny,xylim[2],-xylim[3]);
   for (Int_t ipix=0; ipix<nPix; ipix++) {
-    pixPtr = (AliMUONPixel*) fPixArray->UncheckedAt(ipix);
+    pixPtr = (AliMUONPixel*) pixArray->UncheckedAt(ipix);
     hist->Fill(pixPtr->Coord(0), pixPtr->Coord(1), pixPtr->Charge());
   }
-  if (fDraw) {
-    ((TCanvas*)gROOT->FindObject("c2"))->cd();
-    gPad->SetTheta(55);
-    gPad->SetPhi(30);
-    hist->Draw("lego1Fb");
-    gPad->Update();
-    int ia;
-    cin >> ia;
-  }
+  if (fDraw && pixArray == fPixArray) fDraw->DrawHist("c2", hist);
 
   Int_t nMax = 0, indx;
   Int_t *isLocalMax = new Int_t[ny*nx];
@@ -2382,11 +2375,11 @@ Int_t AliMUONClusterFinderAZ::FindLocalMaxima(Int_t *localMax, Double_t *maxVal)
       if (isLocalMax[indx+j-1] > 0) { 
 	localMax[nMax] = indx + j - 1; 
 	maxVal[nMax++] = hist->GetCellContent(j,i);
+	if (nMax > 99) AliFatal(" Too many local maxima !!!");
       }
-      if (nMax > 99) { cout << " Too many local maxima !!!" << endl; ::exit(0); }
     }
   }
-  cout << " Local max: " << nMax << endl;
+  if (fDebug) cout << " Local max: " << nMax << endl;
   delete [] isLocalMax; isLocalMax = 0;
   return nMax;
 }
@@ -2399,27 +2392,29 @@ void AliMUONClusterFinderAZ::FlagLocalMax(TH2D *hist, Int_t i, Int_t j, Int_t *i
   Int_t nx = hist->GetNbinsX();
   Int_t ny = hist->GetNbinsY();
   Int_t cont = TMath::Nint (hist->GetCellContent(j,i));
-  Int_t cont1 = 0;
+  Int_t cont1 = 0, indx = (i-1)*nx+j-1, indx1 = 0, indx2 = 0;
 
   for (Int_t i1=i-1; i1<i+2; i1++) {
     if (i1 < 1 || i1 > ny) continue;
+    indx1 = (i1 - 1) * nx;
     for (Int_t j1=j-1; j1<j+2; j1++) {
       if (j1 < 1 || j1 > nx) continue;
       if (i == i1 && j == j1) continue;
+      indx2 = indx1 + j1 - 1;
       cont1 = TMath::Nint (hist->GetCellContent(j1,i1));
-      if (cont < cont1) { isLocalMax[(i-1)*nx+j-1] = -1; return; }
-      else if (cont > cont1) isLocalMax[(i1-1)*nx+j1-1] = -1;
+      if (cont < cont1) { isLocalMax[indx] = -1; return; }
+      else if (cont > cont1) isLocalMax[indx2] = -1;
       else { // the same charge
-	isLocalMax[(i-1)*nx+j-1] = 1; 
-	if (isLocalMax[(i1-1)*nx+j1-1] == 0) {
+	isLocalMax[indx] = 1; 
+	if (isLocalMax[indx2] == 0) {
 	  FlagLocalMax(hist, i1, j1, isLocalMax);
-	  if (isLocalMax[(i1-1)*nx+j1-1] < 0) { isLocalMax[(i-1)*nx+j-1] = -1; return; }
-	  else isLocalMax[(i1-1)*nx+j1-1] = -1;
+	  if (isLocalMax[indx2] < 0) { isLocalMax[indx] = -1; return; }
+	  else isLocalMax[indx2] = -1;
 	}
       } 
     }
   }
-  isLocalMax[(i-1)*nx+j-1] = 1; // local maximum
+  isLocalMax[indx] = 1; // local maximum
 }
 
 //_____________________________________________________________________________
@@ -2454,7 +2449,7 @@ void AliMUONClusterFinderAZ::FindCluster(Int_t *localMax, Int_t iMax)
     ((AliMUONPixel*)fPixArray->UncheckedAt(i))->SetSize(0,wx); 
     ((AliMUONPixel*)fPixArray->UncheckedAt(i))->SetSize(1,wy); 
   }
-  cout << iMax << " " << nPix << endl;
+  if (fDebug) cout << iMax << " " << nPix << endl;
 
   Float_t xy[4], xy12[4];
   // Pick up pads which overlap with found pixels
@@ -2469,3 +2464,602 @@ void AliMUONClusterFinderAZ::FindCluster(Int_t *localMax, Int_t iMax)
 
   delete [] used; used = 0;
 }
+
+//_____________________________________________________________________________
+AliMUONClusterFinderAZ&  
+AliMUONClusterFinderAZ::operator=(const AliMUONClusterFinderAZ& rhs)
+{
+// Protected assignement operator
+
+  if (this == &rhs) return *this;
+
+  AliFatal("Not implemented.");
+    
+  return *this;  
+}    
+          
+//_____________________________________________________________________________
+void AliMUONClusterFinderAZ::AddVirtualPad()
+{
+  // Add virtual pad (with small charge) to improve fit for some
+  // clusters (when pad with max charge is at the extreme of the cluster)
+
+  // Get number of pads in X and Y-directions
+  Int_t nInX = -1, nInY;
+  PadsInXandY(nInX, nInY);
+  //return;
+
+  // Add virtual pad only if number of pads per direction == 2
+  if (nInX != 2 && nInY != 2) return;
+
+  // Find pads with max charge
+  Int_t maxpad[2][2] = {{-1, -1}, {-1, -1}}, cath;
+  Double_t sigmax[2] = {0}, aamax[2] = {0};
+  for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
+    if (fPadIJ[1][j] != 0) continue;
+    cath = fPadIJ[0][j];
+    if (fXyq[2][j] > sigmax[cath]) {
+      maxpad[cath][1] = maxpad[cath][0];
+      aamax[cath] = sigmax[cath];
+      sigmax[cath] = fXyq[2][j];
+      maxpad[cath][0] = j;
+    }
+  }
+  if (maxpad[0][0] >= 0 && maxpad[0][1] < 0 || maxpad[1][0] >= 0 && maxpad[1][1] < 0) {
+    for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
+      if (fPadIJ[1][j] != 0) continue;
+      cath = fPadIJ[0][j];
+      if (j == maxpad[cath][0] || j == maxpad[cath][1]) continue;
+      if (fXyq[2][j] > aamax[cath]) {
+	aamax[cath] = fXyq[2][j];
+	maxpad[cath][1] = j;
+      }
+    }
+  }
+  // Check for mirrors (side X on cathode 0) 
+  Bool_t mirror = kFALSE;
+  if (maxpad[0][0] >= 0 && maxpad[1][0] >= 0) {
+    mirror = fXyq[3][maxpad[0][0]] < fXyq[4][maxpad[0][0]]; 
+    if (!mirror && TMath::Abs(fXyq[3][maxpad[0][0]]-fXyq[3][maxpad[1][0]]) < 0.001) {
+      // Special case when pads on both cathodes have the same size
+      Int_t yud[2] = {0};
+      for (Int_t j = 0; j < fnPads[0]+fnPads[1]; j++) {
+	cath = fPadIJ[0][j];
+	if (j == maxpad[cath][0]) continue;
+	if (fPadIJ[2][j] != fPadIJ[2][maxpad[cath][0]]) continue;
+	if (fPadIJ[3][j] + 1 == fPadIJ[3][maxpad[cath][0]] || 
+	    fPadIJ[3][j] - 1 == fPadIJ[3][maxpad[cath][0]]) yud[cath]++;
+      }
+      if (!yud[0]) mirror = kTRUE; // take the other cathode
+    } // if (!mirror &&...
+  } // if (maxpad[0][0] >= 0 && maxpad[1][0] >= 0)
+
+  // Find neughbours of pads with max charges
+  Int_t nn, xList[10], yList[10], ix0, iy0, ix, iy, neighb;
+  for (cath=0; cath<2; cath++) {
+    if (!cath && maxpad[0][0] < 0) continue; // one-sided cluster - cathode 1
+    if (cath && maxpad[1][0] < 0) break; // one-sided cluster - cathode 0
+    if (maxpad[1][0] >= 0) {
+      if (!mirror) {
+	if (!cath && nInY != 2) continue;
+	if (cath && nInX != 2 && (maxpad[0][0] >= 0 || nInY != 2)) continue;
+      } else {
+	if (!cath && nInX != 2) continue;
+	if (cath && nInY != 2 && (maxpad[0][0] >= 0 || nInX != 2)) continue;
+      }
+    }
+
+    Int_t iAddX = 0, iAddY = 0, ix1 = 0, iy1 = 0, iPad = 0;
+    if (maxpad[0][0] < 0) iPad = 1;
+
+    for (iPad=0; iPad<2; iPad++) {
+      if (maxpad[cath][iPad] < 0) continue;
+      if (iPad && !iAddX && !iAddY) break;
+      if (iPad && fXyq[2][maxpad[cath][1]] / sigmax[cath] < 0.5) break;
+
+      Int_t neighbx = 0, neighby = 0;
+      ix0 = fPadIJ[2][maxpad[cath][iPad]];
+      iy0 = fPadIJ[3][maxpad[cath][iPad]];
+      fSegmentation[cath]->Neighbours(ix0, iy0, &nn, xList, yList); 
+      Float_t zpad; 
+      for (Int_t j=0; j<nn; j++) {
+	if (TMath::Abs(xList[j]-ix0) == 1 || xList[j]*ix0 == -1) neighbx++;
+	if (TMath::Abs(yList[j]-iy0) == 1 || yList[j]*iy0 == -1) neighby++;
+      }
+      if (!mirror) {
+	if (cath) neighb = neighbx; 
+	else neighb = neighby;
+	if (maxpad[0][0] < 0) neighb += neighby;
+	else if (maxpad[1][0] < 0) neighb += neighbx;
+      } else {
+	if (!cath) neighb = neighbx; 
+	else neighb = neighby;
+	if (maxpad[0][0] < 0) neighb += neighbx;
+	else if (maxpad[1][0] < 0) neighb += neighby;
+      }
+
+      for (Int_t j=0; j<fnPads[0]+fnPads[1]; j++) {
+	if (fPadIJ[0][j] != cath) continue;
+	ix = fPadIJ[2][j];
+	iy = fPadIJ[3][j];
+	if (iy == iy0 && ix == ix0) continue; 
+	for (Int_t k=0; k<nn; k++) {
+	  if (xList[k] != ix || yList[k] != iy) continue;
+	  if (!mirror) {
+	    if ((!cath || maxpad[0][0] < 0) && 
+		(TMath::Abs(iy-iy0) == 1 || iy*iy0 == -1)) {
+	      if (!iPad && TMath::Abs(ix-ix0) == 1 || ix*ix0 == -1) ix1 = xList[k]; //19-12-05 
+	      xList[k] = yList[k] = 0; 
+	      neighb--;
+	      break;
+	    }
+	    if ((cath || maxpad[1][0] < 0) && 
+		(TMath::Abs(ix-ix0) == 1 || ix*ix0 == -1)) {
+	      if (!iPad) ix1 = xList[k]; //19-12-05
+	      xList[k] = yList[k] = 0; 
+	      neighb--;
+	    }
+	  } else {
+	    if ((!cath || maxpad[0][0] < 0) && 
+		(TMath::Abs(ix-ix0) == 1 || ix*ix0 == -1)) {
+	      if (!iPad) ix1 = xList[k]; //19-12-05
+	      xList[k] = yList[k] = 0; 
+	      neighb--;
+	      break;
+	    }
+	    if ((cath || maxpad[1][0] < 0) && 
+		(TMath::Abs(iy-iy0) == 1 || iy*iy0 == -1)) {
+	      xList[k] = yList[k] = 0; 
+	      neighb--;
+	    }
+	  }
+	  break;
+	} // for (Int_t k=0; k<nn;
+	if (!neighb) break;
+      } // for (Int_t j=0; j<fnPads[0]+fnPads[1];
+      if (!neighb) continue;
+      
+      // Add virtual pad
+      Int_t npads, isec;
+      isec = 0;
+      for (Int_t j=0; j<nn; j++) {
+	if (xList[j] == 0 && yList[j] == 0) continue;
+	npads = fnPads[0] + fnPads[1];
+	fPadIJ[0][npads] = cath;
+	fPadIJ[1][npads] = 0;
+	ix = xList[j]; 
+	iy = yList[j];
+	if (TMath::Abs(ix-ix0) == 1 || ix*ix0 == -1) {
+	  if (iy != iy0) continue; // new segmentation - check
+	  if (nInX != 2) continue; // new
+	  if (!mirror) {
+	    if (!cath && maxpad[1][0] >= 0) continue;
+	  } else {
+	    if (cath && maxpad[0][0] >= 0) continue;
+	  }
+	  if (iPad && !iAddX) continue;
+          fSegmentation[cath]->GetPadC(ix, iy, fXyq[0][npads], fXyq[1][npads], zpad);
+	  if (fXyq[0][npads] > 1.e+5) continue; // temporary fix
+	  if (ix == ix1) continue; //19-12-05
+	  if (ix1 == ix0) continue;
+	  if (maxpad[1][0] < 0 || mirror && maxpad[0][0] >= 0) {
+	    if (!iPad) fXyq[2][npads] = TMath::Min (sigmax[0]/100, 5.);
+	    else fXyq[2][npads] = TMath::Min (aamax[0]/100, 5.);
+	  }
+	  else {
+	    if (!iPad) fXyq[2][npads] = TMath::Min (sigmax[1]/100, 5.);
+	    else fXyq[2][npads] = TMath::Min (aamax[1]/100, 5.);
+	  }
+	  fXyq[2][npads] = TMath::Max (fXyq[2][npads], (float)1);
+	  fXyq[3][npads] = -2; // flag
+	  fPadIJ[2][npads] = ix;
+	  fPadIJ[3][npads] = iy;
+	  fnPads[1]++;
+	  iAddX = npads;
+	  if (fDebug) printf(" ***** Add virtual pad in X ***** %f %f %f %3d %3d \n", fXyq[2][npads], 
+			     fXyq[0][npads], fXyq[1][npads], ix, iy);
+	  ix1 = ix0;
+	  continue;
+	} 
+	if (nInY != 2) continue;
+	if (!mirror && cath && maxpad[0][0] >= 0) continue;
+	if (mirror && !cath && maxpad[1][0] >= 0) continue;
+	if (TMath::Abs(iy-iy0) == 1 || TMath::Abs(iy*iy0) == 1) {
+	  if (ix != ix0) continue; // new segmentation - check
+	  if (iPad && !iAddY) continue;
+          fSegmentation[cath]->GetPadC(ix, iy, fXyq[0][npads], fXyq[1][npads], zpad);
+	  if (iy1 == iy0) continue;
+	  //if (iPad && iy1 == iy0) continue;
+	  if (maxpad[0][0] < 0 || mirror && maxpad[1][0] >= 0) {
+	    if (!iPad) fXyq[2][npads] = TMath::Min (sigmax[1]/15, fgkZeroSuppression);
+	    else fXyq[2][npads] = TMath::Min (aamax[1]/15, fgkZeroSuppression);
+	  }
+	  else {
+	    if (!iPad) fXyq[2][npads] = TMath::Min (sigmax[0]/15, fgkZeroSuppression);
+	    else fXyq[2][npads] = TMath::Min (aamax[0]/15, fgkZeroSuppression);
+	  }
+	  fXyq[2][npads] = TMath::Max (fXyq[2][npads], (float)1);
+	  fXyq[3][npads] = -2; // flag
+	  fPadIJ[2][npads] = ix;
+	  fPadIJ[3][npads] = iy;
+	  fnPads[1]++;
+	  iAddY = npads;
+	  if (fDebug) printf(" ***** Add virtual pad in Y ***** %f %f %f %3d %3d \n", fXyq[2][npads], 
+			     fXyq[0][npads], fXyq[1][npads], ix, iy);
+	  iy1 = iy0;
+	}
+      } // for (Int_t j=0; j<nn;
+    } // for (Int_t iPad=0;
+  } // for (cath=0; cath<2;
+  return;
+}
+
+//_____________________________________________________________________________
+void AliMUONClusterFinderAZ::PadsInXandY(Int_t &nInX, Int_t &nInY)
+{
+  // Find number of pads in X and Y-directions (excluding virtual ones and
+  // overflows)
+
+  static Int_t nXsaved = 0, nYsaved = 0;
+  nXsaved = nYsaved = 0;
+  //if (nInX >= 0) {nInX = nXsaved; nInY = nYsaved; return; }
+  Float_t *xPad0 = NULL, *yPad0 = NULL, *xPad1 = NULL, *yPad1 = NULL;
+  Float_t wMinX[2] = {99, 99}, wMinY[2] = {99, 99};
+  Int_t *nPad0 = NULL, *nPad1 = NULL;
+  Int_t nPads = fnPads[0] + fnPads[1];
+  if (fnPads[0]) {
+    xPad0 = new Float_t[nPads];
+    yPad0 = new Float_t[nPads];
+    nPad0 = new Int_t[nPads];
+  }
+  if (fnPads[1]) {
+    xPad1 = new Float_t[nPads];
+    yPad1 = new Float_t[nPads];
+    nPad1 = new Int_t[nPads];
+  }
+  Int_t n0 = 0, n1 = 0, cath, npadx[2] = {1, 1}, npady[2] = {1, 1};
+  for (Int_t j = 0; j < nPads; j++) {
+    if (nInX < 0 && fPadIJ[1][j] != 0) continue; // before fit
+    else if (nInX == 0 && fPadIJ[1][j] != 1) continue; // fit - exclude overflows
+    else if (nInX > 0 && fPadIJ[1][j] != 1 && fPadIJ[1][j] != -9) continue; // exclude non-marked
+    if (nInX <= 0 && fXyq[2][j] > fgkSaturation-1) continue; // skip overflows
+    cath = fPadIJ[0][j];
+    if (fXyq[3][j] > 0) { // exclude virtual pads
+      wMinX[cath] = TMath::Min (wMinX[cath], fXyq[3][j]);
+      wMinY[cath] = TMath::Min (wMinY[cath], fXyq[4][j]);
+      //20-12-05 }
+      if (cath) { xPad1[n1] = fXyq[0][j]; yPad1[n1++] = fXyq[1][j]; }
+      else { xPad0[n0] = fXyq[0][j]; yPad0[n0++] = fXyq[1][j]; }
+    }
+  }
+
+  // Sort
+  if (n0) { 
+    TMath::Sort (n0, xPad0, nPad0); // in X
+    for (Int_t i = 1; i < n0; i++) 
+      if (xPad0[nPad0[i]] - xPad0[nPad0[i-1]] < -0.01) npadx[0]++;
+    TMath::Sort (n0, yPad0, nPad0); // in Y
+    for (Int_t i = 1; i < n0; i++) 
+      if (yPad0[nPad0[i]] - yPad0[nPad0[i-1]] < -0.01) npady[0]++;
+  }
+  
+  if (n1) { 
+    TMath::Sort (n1, xPad1, nPad1); // in X
+    for (Int_t i = 1; i < n1; i++) 
+      if (xPad1[nPad1[i]] - xPad1[nPad1[i-1]] < -0.01) npadx[1]++;
+    TMath::Sort (n1, yPad1, nPad1); // in Y
+    for (Int_t i = 1; i < n1; i++) 
+      if (yPad1[nPad1[i]] - yPad1[nPad1[i-1]] < -0.01) npady[1]++;
+  }
+  if (fnPads[0]) { delete [] xPad0; delete [] yPad0; delete [] nPad0; }
+  if (fnPads[1]) { delete [] xPad1; delete [] yPad1; delete [] nPad1; }
+  if (TMath::Abs (wMinY[0] - wMinY[1]) < 1.e-3) nInY = TMath::Max (npady[0], npady[1]);
+  else nInY = wMinY[0] < wMinY[1] ? npady[0] : npady[1];
+  if (TMath::Abs (wMinX[0] - wMinX[1]) < 1.e-3) nInX = TMath::Max (npadx[0], npadx[1]);
+  else nInX = wMinX[0] < wMinX[1] ? npadx[0] : npadx[1];
+}
+
+//_____________________________________________________________________________
+void AliMUONClusterFinderAZ::Simple()
+{
+  // Process simple cluster (small number of pads) without EM-procedure
+
+  Int_t nForFit = 1, clustFit[1] = {0}, nfit;
+  Double_t parOk[3] = {0.}; 
+  TObjArray *clusters[1]; 
+  clusters[0] = fPixArray;
+  for (Int_t i = 0; i < fnPads[0]+fnPads[1]; i++) {
+    if (fXyq[2][i] > fgkSaturation-1) fPadIJ[1][i] = -9;
+    else fPadIJ[1][i] = 1;
+  }
+  nfit = Fit(1, nForFit, clustFit, clusters, parOk);
+}
+
+//_____________________________________________________________________________
+void AliMUONClusterFinderAZ::Errors(AliMUONRawCluster *clus)
+{
+  // Correct reconstructed coordinates for some clusters and evaluate errors
+
+  Double_t qTot = clus->GetCharge(0), fmin = clus->GetChi2(0);
+  Double_t xreco = clus->GetX(0), yreco = clus->GetY(0), zreco = clus->GetZ(0);
+  Double_t sigmax[2] = {0};
+
+  Int_t nInX = 1, nInY, maxdig[2] ={-1, -1}, digit, cath1, isec;
+  PadsInXandY(nInX, nInY);
+
+  // Find pad with maximum signal
+  for (Int_t cath = 0; cath < 2; cath++) {
+    for (Int_t j = 0; j < clus->GetMultiplicity(cath); j++) {
+      cath1 = cath;
+      digit = clus->GetIndex(j, cath);
+      if (digit < 0) { cath1 = TMath::Even(cath); digit = -digit - 1; } // from the other cathode
+
+      if (clus->GetContrib(j,cath) > sigmax[cath1]) {
+	sigmax[cath1] = clus->GetContrib(j,cath);
+	maxdig[cath1] = digit;
+      }
+    }
+  }
+
+  // Size of pad with maximum signal and reco coordinate distance from the pad center
+  AliMUONDigit *mdig = 0;
+  Double_t wx[2], wy[2], dxc[2], dyc[2];
+  Float_t xpad, ypad, zpad;
+  Int_t ix, iy;
+  for (Int_t cath = 0; cath < 2; cath++) {
+    if (maxdig[cath] < 0) continue;
+    mdig = fInput->Digit(cath,maxdig[cath]);
+    isec = fSegmentation[cath]->Sector(mdig->PadX(), mdig->PadY());
+    wx[cath] = fSegmentation[cath]->Dpx(isec);
+    wy[cath] = fSegmentation[cath]->Dpy(isec);
+    fSegmentation[cath]->GetPadI(xreco, yreco, zreco, ix, iy);
+    isec = fSegmentation[cath]->Sector(ix, iy);
+    if (isec > 0) {
+      fSegmentation[cath]->GetPadC(ix, iy, xpad, ypad, zpad);
+      dxc[cath] = xreco - xpad;
+      dyc[cath] = yreco - ypad;
+    }
+  }
+
+  // Check if pad with max charge at the edge (number of neughbours)
+  Int_t nn, xList[10], yList[10], neighbx[2][2] = {{0,0}, {0,0}}, neighby[2][2]= {{0,0}, {0,0}};
+  for (Int_t cath = 0; cath < 2; cath++) {
+    if (maxdig[cath] < 0) continue;
+    mdig = fInput->Digit(cath,maxdig[cath]);
+    fSegmentation[cath]->Neighbours(mdig->PadX(), mdig->PadY(), &nn, xList, yList); 
+    isec = fSegmentation[cath]->Sector(mdig->PadX(), mdig->PadY());
+    /*??
+    Float_t sprX = fResponse->SigmaIntegration() * fResponse->ChargeSpreadX();
+    Float_t sprY = fResponse->SigmaIntegration() * fResponse->ChargeSpreadY();
+    //fSegmentation[cath]->FirstPad(fInput->DetElemId(),muons[ihit][1], muons[ihit][2], muons[ihit][3], sprX, sprY);  
+    //fSegmentation[cath]->FirstPad(fInput->DetElemId(),xreco, yreco, zreco, sprX, sprY);  
+    fSegmentation[cath]->FirstPad(xreco, yreco, zreco, sprX, sprY);  
+    Int_t border = 0;
+    //if (fSegmentation[cath]->Sector(fInput->DetElemId(),fSegmentation[cath]->Ix(),fSegmentation[cath]->Iy()) <= 0) {
+    if (fSegmentation[cath]->Sector(fSegmentation[cath]->Ix(), fSegmentation[cath]->Iy()) <= 0) {
+      //fSegmentation[cath]->NextPad(fInput->DetElemId());
+      fSegmentation[cath]->NextPad();
+      border = 1;
+    } 
+    */
+    for (Int_t j=0; j<nn; j++) {
+      //if (border && yList[j] < fSegmentation[cath]->Iy()) continue;
+      fSegmentation[cath]->GetPadC(xList[j], yList[j], xpad, ypad, zpad);
+      //cout << ch << " " << xList[j] << " " << yList[j] << " " << border << " " << x << " " << y << " " << xpad << " " << ypad << endl;
+      if (TMath::Abs(xpad) < 1 && TMath::Abs(ypad) < 1) continue;
+      if (xList[j] == mdig->PadX()-1 || mdig->PadX() == 1 && 
+	  xList[j] == -1) neighbx[cath][0] = 1;
+      else if (xList[j] == mdig->PadX()+1 || mdig->PadX() == -1 && 
+	       xList[j] == 1) neighbx[cath][1] = 1;
+      if (yList[j] == mdig->PadY()-1 || mdig->PadY() == 1 &&
+	  yList[j] == -1) neighby[cath][0] = 1;
+      else if (yList[j] == mdig->PadY()+1 || mdig->PadY() == -1 &&
+	       yList[j] == 1) neighby[cath][1] = 1;
+    } // for (Int_t j=0; j<nn;
+    if (neighbx[cath][0] && neighbx[cath][1]) neighbx[cath][0] = 0;
+    else if (neighbx[cath][1]) neighbx[cath][0] = -1;
+    else neighbx[cath][0] = 1;
+    if (neighby[cath][0] && neighby[cath][1]) neighby[cath][0] = 0;
+    else if (neighby[cath][1]) neighby[cath][0] = -1;
+    else neighby[cath][0] = 1;
+  }
+
+  Int_t iOver = clus->GetClusterType();
+  // One-sided cluster
+  if (!clus->GetMultiplicity(0)) {
+    neighby[0][0] = neighby[1][0];
+    wy[0] = wy[1];
+    if (iOver < 99) iOver += 100 * iOver;
+    dyc[0] = dyc[1];
+  } else if (!clus->GetMultiplicity(1)) {
+    neighbx[1][0] = neighbx[0][0];
+    wx[1] = wx[0];
+    if (iOver < 99) iOver += 100 * iOver;
+    dxc[1] = dxc[0];
+  }
+
+  // Apply corrections and evaluate errors
+  Double_t errY, errX;
+  Errors(nInY, nInX, neighby[0][0],neighbx[1][0], fmin, wy[0]*10, wx[1]*10, iOver, 
+	 dyc[0], dxc[1], qTot, yreco, xreco, errY, errX);
+  errY = TMath::Max (errY, 0.01);
+  //errY = 0.01;
+  //errX = TMath::Max (errX, 0.144);
+  clus->SetX(0, xreco); clus->SetY(0, yreco);
+  clus->SetErrX(errX); clus->SetErrY(errY);
+}
+
+//_____________________________________________________________________________
+void AliMUONClusterFinderAZ::Errors(Int_t ny, Int_t nx, Int_t iby, Int_t ibx, Double_t fmin,
+				    Double_t wy, Double_t wx, Int_t iover, 
+				    Double_t dyc, Double_t /*dxc*/, Double_t qtot, 
+				    Double_t &yrec, Double_t &xrec, Double_t &erry, Double_t &errx)
+{
+  // Correct reconstructed coordinates for some clusters and evaluate errors
+
+    erry = 0.01;
+    errx = 0.144;
+    Int_t iovery = iover % 100;
+    Double_t corr = 0;
+
+/* ---> Ny = 1 */
+    if (ny == 1) {
+      if (iby != 0) {
+	// edge effect 
+	yrec += iby * (0.1823+0.2008)/2;
+	erry = 0.04587;
+      } else {
+	// Find "effective pad width" 
+	Double_t width = 0.218 / (1.31e-4 * TMath::Exp (2.688 * TMath::Log(qtot)) + 1) * 2;
+	width = TMath::Min (width, 0.4);
+	erry = width / TMath::Sqrt(12.);
+	erry = TMath::Max (erry, 0.01293);
+      }
+      goto x; //return;
+    }
+
+/* ---> "Bad" fit */
+    if (fmin > 0.4) {
+      erry = 0.1556;
+      if (ny == 5) erry = 0.06481;
+      goto x; //return;
+    }
+
+/* ---> By != 0 */
+    if (iby != 0) {
+      if (ny > 2) {
+	erry = 0.00417; //0.01010
+      } else {
+        // ny = 2 
+	if (dyc * iby > -0.05) {
+	  Double_t dyc2 = dyc * dyc;
+	  if (iby < 0) {
+	    corr = 0.019 - 0.602 * dyc + 8.739 * dyc2 - 44.209 * dyc2 * dyc;
+	    corr = TMath::Min (corr, TMath::Abs(-0.25-dyc));
+	    yrec -= corr;
+	    //dyc -= corr;
+	    erry = 0.00814;
+	  } else {
+	    corr = 0.006 + 0.300 * dyc + 6.147 * dyc2 + 42.039 * dyc2 * dyc;
+	    corr = TMath::Min (corr, 0.25-dyc);
+	    yrec += corr;
+	    //dyc += corr;
+	    erry = 0.01582;
+	  }
+	} else {
+	  erry = (0.00303 + 0.00296) / 2;
+	}
+      }
+      goto x; //return;
+    }
+
+/* ---> Overflows */
+    if (iovery != 0) {
+      if (qtot < 3000) {
+	erry = 0.0671;
+      } else {
+	if (iovery > 1) {
+	  erry = 0.09214;
+	} else if (TMath::Abs(wy - 5) < 0.1) {
+	  erry = 0.061; //0.06622
+	} else {
+	  erry = 0.00812; // 0.01073 
+	}
+      }
+      goto x; //return;
+    }
+
+/* ---> "Good" but very high signal */
+    if (qtot > 4000) {
+      if (TMath::Abs(wy - 4) < 0.1) {
+	erry = 0.00117;
+      } else if (fmin < 0.03 && qtot < 6000) {
+	erry = 0.01003;
+      } else {
+	erry = 0.1931;
+      }
+      goto x; //return;
+    }
+
+/* ---> "Good" clusters */
+    if (ny > 3) {
+      if (TMath::Abs(wy - 5) < 0.1) {
+	erry = 0.0011; //0.00304 
+      } else if (qtot < 400.) {
+	erry = 0.0165;
+      } else {
+	erry = 0.00135; // 0.00358 
+      }
+    } else if (ny == 3) {
+      if (TMath::Abs(wy - 4) < 0.1) {
+	erry = 35.407 / (1 + TMath::Exp(5.511*TMath::Log(qtot/265.51))) + 11.564;
+	//erry = 83.512 / (1 + TMath::Exp(3.344*TMath::Log(qtot/211.58))) + 12.260;
+      } else {
+	erry = 147.03 / (1 + TMath::Exp(1.713*TMath::Log(qtot/73.151))) + 9.575;
+	//erry = 91.743 / (1 + TMath::Exp(2.332*TMath::Log(qtot/151.67))) + 11.453;
+      }
+      erry *= 1.e-4;
+    } else {
+      // ny = 2 
+      if (TMath::Abs(wy - 4) < 0.1) {
+	erry = 60.800 / (1 + TMath::Exp(3.305*TMath::Log(qtot/104.53))) + 11.702;
+	//erry = 73.128 / (1 + TMath::Exp(5.676*TMath::Log(qtot/120.93))) + 17.839;
+      } else {
+	erry = 117.98 / (1 + TMath::Exp(2.005*TMath::Log(qtot/37.649))) + 21.431;
+	//erry = 99.066 / (1 + TMath::Exp(4.900*TMath::Log(qtot/107.57))) + 25.315;
+      }
+      erry *= 1.e-4;
+    }
+    //return;
+
+ x:
+/* ---> X-coordinate */
+/* ---> Y-side */    
+    if (wx > 11) { 
+      errx = 0.0036;
+      xrec -= 0.1385;
+      return;
+    }
+/* ---> Nx = 1 */
+    if (nx == 1) {
+      if (TMath::Abs(wx - 6) < 0.1) {
+	if (qtot < 40) errx = 0.1693;
+	else errx = 0.06241;
+      } else if (TMath::Abs(wx - 7.5) < 0.1) {
+	if (qtot < 40) errx = 0.2173;
+	else errx = 0.07703;
+      } else if (TMath::Abs(wx - 10) < 0.1) {
+	if (ibx == 0) {
+	  if (qtot < 40) errx = 0.2316;
+	  else errx = 0.1426;
+	} else {
+	  xrec += (0.2115 + 0.1942) / 2 * ibx;
+	  errx = 0.1921;
+	}
+      }
+      return;
+    }
+/* ---> "Bad" fit */
+    if (fmin > 0.5) {
+      errx = 0.1591;
+      return;
+    }
+/* ---> Bx != 0 */
+    if (ibx != 0) {
+      if (ibx > 0) { errx = 0.06761; xrec -= 0.03832; }
+      else { errx = 0.06653; xrec += 0.02581; }
+      return;
+    }
+/* ---> Overflows */
+    if (iover != 0) {
+      if (TMath::Abs(wx - 6) < 0.1) errx = 0.06979;
+      else if (TMath::Abs(wx - 7.5) < 0.1) errx = 0.1089;
+      else if (TMath::Abs(wx - 10) < 0.1) errx = 0.09847;
+      return;
+    }
+/* ---> Good */
+    if (TMath::Abs(wx - 6) < 0.1) errx = 0.06022;
+    else if (TMath::Abs(wx - 7.5) < 0.1) errx = 0.07247;
+    else if (TMath::Abs(wx - 10) < 0.1) errx = 0.07359;
+}
+