/**************************************************************************
 * 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.                  *
 **************************************************************************/

#include <iostream.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <TSystem.h>
#include <TROOT.h>
#include <TStopwatch.h>
#include <TCanvas.h>
#include <TF1.h>
#include <TRandom.h>
#include <TH1.h>
#include <TFile.h>
#include <TVector.h>
#include <TArrayI.h>
#include <TArrayF.h>

#include "AliRun.h"
#include "AliITS.h"
#include "AliITShit.h"
#include "AliITSdigit.h"
#include "AliITSmodule.h"
#include "AliITSpList.h"
#include "AliITSMapA1.h"
#include "AliITSMapA2.h"
#include "AliITSetfSDD.h"
#include "AliITSRawData.h"
#include "AliITSHuffman.h"
#include "AliITSsegmentation.h"
#include "AliITSresponse.h"
#include "AliITSsegmentationSDD.h"
#include "AliITSresponseSDD.h"
#include "AliITSsimulationSDD.h"

ClassImp(AliITSsimulationSDD)
////////////////////////////////////////////////////////////////////////
// Version: 0
// Written by Piergiorgio Cerello
// November 23 1999
//
// AliITSsimulationSDD is the simulation of SDDs.
  //
//Begin_Html
/*
<img src="picts/ITS/AliITShit_Class_Diagram.gif">
</pre>
<br clear=left>
<font size=+2 color=red>
<p>This show the relasionships between the ITS hit class and the rest of Aliroot.
</font>
<pre>
*/
//End_Html
//______________________________________________________________________
Int_t power(Int_t b, Int_t e) {
    // compute b to the e power, where both b and e are Int_ts.
    Int_t power = 1,i;

    for(i=0; i<e; i++) power *= b;
    return power;
}
//______________________________________________________________________
void FastFourierTransform(AliITSetfSDD *alisddetf,Double_t *real,
                          Double_t *imag,Int_t direction) {
    // Do a Fast Fourier Transform

    Int_t samples = alisddetf->GetSamples();
    Int_t l = (Int_t) ((log((Float_t) samples)/log(2.))+0.5);
    Int_t m1 = samples;
    Int_t m  = samples/2;
    Int_t m2 = samples/m1;
    Int_t i,j,k;
    for(i=1; i<=l; i++) {
	for(j=0; j<samples; j += m1) {
	    Int_t p = 0;
	    for(k=j; k<= j+m-1; k++) {
		Double_t wsr = alisddetf->GetWeightReal(p);
		Double_t wsi = alisddetf->GetWeightImag(p);
		if(direction == -1) wsi = -wsi;
		Double_t xr = *(real+k+m);
		Double_t xi = *(imag+k+m);
		*(real+k+m) = wsr*(*(real+k)-xr) - wsi*(*(imag+k)-xi);
		*(imag+k+m) = wsr*(*(imag+k)-xi) + wsi*(*(real+k)-xr);
		*(real+k) += xr;
		*(imag+k) += xi;
		p += m2;
	    } // end for k
	} // end for j
	m1 = m;
	m /= 2;
	m2 += m2;
    } // end for i
  
    for(j=0; j<samples; j++) {
	Int_t j1 = j;
	Int_t p = 0;
	Int_t i1;
	for(i1=1; i1<=l; i1++) {
	    Int_t j2 = j1;
	    j1 /= 2;
	    p = p + p + j2 - j1 - j1;
	} // end for i1
	if(p >= j) {
	    Double_t xr = *(real+j);
	    Double_t xi = *(imag+j);
	    *(real+j) = *(real+p);
	    *(imag+j) = *(imag+p);
	    *(real+p) = xr;
	    *(imag+p) = xi;
	} // end if p>=j
    } // end for j
    if(direction == -1) {
	for(i=0; i<samples; i++) {
	    *(real+i) /= samples;
	    *(imag+i) /= samples;
	} // end for i
    } // end if direction == -1
  return;
}
//______________________________________________________________________
AliITSsimulationSDD::AliITSsimulationSDD(){
    // Default constructor

    fResponse      = 0;
    fSegmentation  = 0;
    fHis           = 0;
    fHitMap1       = 0;
    fHitMap2       = 0;
    fElectronics   = 0;
    fStream        = 0;
    fInZR          = 0;
    fInZI          = 0;
    fOutZR         = 0;
    fOutZI         = 0;
    fNofMaps       = 0;
    fMaxNofSamples = 0;
    fITS           = 0;
    fTreeB        = 0;
    fD.Set(0);
    fT1.Set(0);
    fT2.Set(0);
    fTol.Set(0);
    fNoise.Set(0);
    fBaseline.Set(0);
    SetScaleFourier();
    SetPerpendTracksFlag();
    SetDoFFT();
    SetCheckNoise();
}
//______________________________________________________________________
AliITSsimulationSDD::AliITSsimulationSDD(AliITSsimulationSDD &source){
    // Copy constructor to satify Coding roules only.

    if(this==&source) return;
    Error("AliITSsimulationSSD","Not allowed to make a copy of "
	  "AliITSsimulationSDD Using default creater instead");
    AliITSsimulationSDD();
}
//______________________________________________________________________
AliITSsimulationSDD& AliITSsimulationSDD::operator=(AliITSsimulationSDD &src){
    // Assignment operator to satify Coding roules only.

    if(this==&src) return *this;
    Error("AliITSsimulationSSD","Not allowed to make a = with "
	  "AliITSsimulationSDD Using default creater instead");
    return *this ;
}
//______________________________________________________________________
AliITSsimulationSDD::AliITSsimulationSDD(AliITSsegmentation *seg,
					 AliITSresponse *resp){
    // Standard Constructor


    fResponse      = 0;
    fSegmentation  = 0;
    fHis           = 0;
    fHitMap1       = 0;
    fHitMap2       = 0;
    fElectronics   = 0;
    fStream        = 0;
    fInZR          = 0;
    fInZI          = 0;
    fOutZR         = 0;
    fOutZI         = 0;
    fNofMaps       = 0;
    fMaxNofSamples = 0;
    fITS           = 0;
    fTreeB         = 0;

    Init((AliITSsegmentationSDD*)seg,(AliITSresponseSDD*)resp);
}
//______________________________________________________________________
void AliITSsimulationSDD::Init(AliITSsegmentationSDD *seg,
			       AliITSresponseSDD *resp){
    // Standard Constructor

    fResponse     = resp;
    fSegmentation = seg;
    SetScaleFourier();
    SetPerpendTracksFlag();
    SetDoFFT();
    SetCheckNoise();

    fHitMap2 = new AliITSMapA2(fSegmentation,fScaleSize,1);
    fHitMap1 = new AliITSMapA1(fSegmentation);

    fNofMaps = fSegmentation->Npz();
    fMaxNofSamples = fSegmentation->Npx();

    Float_t sddLength = fSegmentation->Dx();
    Float_t sddWidth  = fSegmentation->Dz();

    Int_t dummy        = 0;
    Float_t anodePitch = fSegmentation->Dpz(dummy);
    Double_t timeStep  = (Double_t)fSegmentation->Dpx(dummy);
    Float_t driftSpeed = fResponse->DriftSpeed();

    if(anodePitch*(fNofMaps/2) > sddWidth) {
	Warning("AliITSsimulationSDD",
		"Too many anodes %d or too big pitch %f \n",
		fNofMaps/2,anodePitch);
    } // end if

    if(timeStep*fMaxNofSamples < sddLength/driftSpeed) {
	Error("AliITSsimulationSDD",
	      "Time Interval > Allowed Time Interval: exit\n");
	return;
    } // end if

    fElectronics = new AliITSetfSDD(timeStep/fScaleSize,
				    fResponse->Electronics());

    char opt1[20], opt2[20];
    fResponse->ParamOptions(opt1,opt2);
    fParam = opt2;
    char *same = strstr(opt1,"same");
    if (same) {
	fNoise.Set(0);
	fBaseline.Set(0);
    } else {
	fNoise.Set(fNofMaps);
	fBaseline.Set(fNofMaps);
    } // end if

    const char *kopt=fResponse->ZeroSuppOption();
    if (strstr(fParam,"file") ) {
	fD.Set(fNofMaps);
	fT1.Set(fNofMaps);
	if (strstr(kopt,"2D")) {
	    fT2.Set(fNofMaps);
            fTol.Set(0);
            Init2D();       // desactivate if param change module by module
	} else if(strstr(kopt,"1D"))  {
            fT2.Set(2);
            fTol.Set(2);
            Init1D();      // desactivate if param change module by module
	} // end if strstr
    } else {
	fD.Set(2);
	fTol.Set(2);
	fT1.Set(2);
	fT2.Set(2);
	SetCompressParam();
    } // end if else strstr

    Bool_t write = fResponse->OutputOption();
    if(write && strstr(kopt,"2D")) MakeTreeB();

    // call here if baseline does not change by module
    // ReadBaseline();

    fITS       = (AliITS*)gAlice->GetModule("ITS");
    Int_t size = fNofMaps*fMaxNofSamples;
    fStream    = new AliITSInStream(size);

    fInZR  = new Double_t [fScaleSize*fMaxNofSamples];
    fInZI  = new Double_t [fScaleSize*fMaxNofSamples];
    fOutZR = new Double_t [fScaleSize*fMaxNofSamples];
    fOutZI = new Double_t [fScaleSize*fMaxNofSamples];  

}
//______________________________________________________________________
AliITSsimulationSDD::~AliITSsimulationSDD() { 
    // destructor

    delete fHitMap1;
    delete fHitMap2;
    delete fStream;
    delete fElectronics;

    fD.Set(0);
    fT1.Set(0);
    fT2.Set(0);
    fTol.Set(0);
    fNoise.Set(0);
    fBaseline.Set(0);
    fITS = 0;

    if (fHis) {
	fHis->Delete(); 
	delete fHis;     
    } // end if fHis
    if(fTreeB) delete fTreeB;           
    if(fInZR)  delete [] fInZR;
    if(fInZI)  delete [] fInZI;	
    if(fOutZR) delete [] fOutZR;
    if(fOutZI) delete [] fOutZI;
}
//______________________________________________________________________
void AliITSsimulationSDD::SDigitiseModule(AliITSmodule *mod,Int_t md,Int_t ev){
    // create maps to build the lists of tracks for each summable digit

    TObjArray *fHits = mod->GetHits();
    Int_t nhits      = fHits->GetEntriesFast();
    fModule          = md;
    fEvent           = ev;

    if(!nhits) return;

    AliITSpList *pList = new AliITSpList(2*fSegmentation->Npz(),
					 fScaleSize*fSegmentation->Npx());

    // inputs to ListOfFiredCells.
    TObjArray          *alist = new TObjArray();
    fHitMap1->SetArray(alist);
    static TClonesArray *padr = 0;
    if(!padr)            padr = new TClonesArray("TVector",1000);

    HitsToAnalogDigits(mod,alist,padr,pList);

    WriteSDigits(pList);

    // clean memory
    alist->Delete();
    delete alist;
    padr->Delete();
    fHitMap1->ClearMap();
    fHitMap2->ClearMap();
}
//______________________________________________________________________
void AliITSsimulationSDD::DigitiseModule(AliITSmodule *mod,Int_t md,Int_t ev){
    // create maps to build the lists of tracks for each digit

    TObjArray *fHits = mod->GetHits();
    Int_t nhits      = fHits->GetEntriesFast();
    fModule          = md;
    fEvent           = ev;

    if (!nhits && fCheckNoise) {
        ChargeToSignal();
        GetNoise();
	fHitMap2->ClearMap();
        return;
    } else if (!nhits) return;

    AliITSpList *pList = new AliITSpList(2*fSegmentation->Npz(),
					 fScaleSize*fSegmentation->Npx());

    // inputs to ListOfFiredCells.
    TObjArray          *alist = new TObjArray();
    fHitMap1->SetArray(alist);
    static TClonesArray *padr = 0;
    if(!padr)            padr = new TClonesArray("TVector",1000);

    HitsToAnalogDigits(mod,alist,padr,pList);

    FinishDigits(alist);

    // clean memory
    alist->Delete();
    delete alist;
    padr->Delete();
    fHitMap1->ClearMap();
    fHitMap2->ClearMap();
}
//______________________________________________________________________
void AliITSsimulationSDD::SDigitsToDigits(AliITSpList *pList){
    // Take Summable digits and create Digits.

    // inputs to ListOfFiredCells.
    TObjArray          *alist = new TObjArray();
    fHitMap1->SetArray(alist);
    static TClonesArray *padr = 0;
    if(!padr)            padr = new TClonesArray("TVector",1000);
    Int_t              arg[6] = {0,0,0,0,0,0};
    Double_t  timeAmplitude;
    Int_t i,j;

    // Fill maps from pList.
    for(i=0;i<pList->GetMaxIndex();i++){
	pList->GetMapIndex(i,arg[0],arg[1]);
	for(j=0;j<pList->GetNEnteries();j++){
	    timeAmplitude = pList->GetTSignal(arg[0],arg[1],j);
	    if(timeAmplitude>0.0) continue;
	    arg[2] = pList->GetTrack(arg[0],arg[1],j);
	    arg[3] = pList->GetHit(arg[0],arg[1],j);
	    ListOfFiredCells(arg,timeAmplitude,alist,padr);
	} // end for j
	// Make sure map has full signal in it.
	fHitMap2->SetHit(arg[0],arg[1],pList->GetSignal(arg[0],arg[1]));
    } // end for i

    FinishDigits(alist);

    // clean memory
    alist->Delete();
    delete alist;
    padr->Delete();
    fHitMap1->ClearMap();
    fHitMap2->ClearMap();
}
//______________________________________________________________________
void AliITSsimulationSDD::FinishDigits(TObjArray *alist){
    // introduce the electronics effects and do zero-suppression if required
    Int_t nentries=alist->GetEntriesFast();

    if(!nentries) return;
    ChargeToSignal();
    const char *kopt=fResponse->ZeroSuppOption();
    ZeroSuppression(kopt);
}
//______________________________________________________________________
void AliITSsimulationSDD::HitsToAnalogDigits(AliITSmodule *mod,TObjArray *alst,
					     TClonesArray *padr,
					     AliITSpList *pList){
    // create maps to build the lists of tracks for each digit

    TObjArray *fHits    = mod->GetHits();
    Int_t      nhits    = fHits->GetEntriesFast();
    Int_t      arg[6]   = {0,0,0,0,0,0};
    Int_t    dummy      = 0;
    Int_t    nofAnodes  = fNofMaps/2;
    Float_t  sddLength  = fSegmentation->Dx();
    Float_t  sddWidth   = fSegmentation->Dz();
    Float_t  anodePitch = fSegmentation->Dpz(dummy);
    Float_t  timeStep   = fSegmentation->Dpx(dummy);
    Float_t  driftSpeed = fResponse->DriftSpeed();
    Float_t  maxadc     = fResponse->MaxAdc();    
    Float_t  topValue   = fResponse->DynamicRange();
    Float_t  cHloss     = fResponse->ChargeLoss();
    Float_t  norm       = maxadc/topValue;
    Float_t  dfCoeff, s1; fResponse->DiffCoeff(dfCoeff,s1); // Signal 2d Shape
    Double_t eVpairs    = 3.6;  // electron pair energy eV.
    Float_t  nsigma     = fResponse->NSigmaIntegration(); //
    Int_t    nlookups   = fResponse->GausNLookUp();       //

    // Piergiorgio's part (apart for few variables which I made float
    // when i thought that can be done
    // Fill detector maps with GEANT hits
    // loop over hits in the module

    const Float_t kconv = 1.0e+6;  // GeV->KeV
    Int_t    itrack      = 0;
    Int_t    hitDetector; // detector number (lay,lad,hitDetector)
    Int_t    iWing;       // which detector wing/side.
    Int_t    detector;    // 2*(detector-1)+iWing
    Int_t    ii,kk,ka,kt; // loop indexs
    Int_t    ia,it,index; // sub-pixel integration indexies
    Int_t    iAnode;      // anode number.
    Int_t    timeSample;  // time buckett.
    Int_t    anodeWindow; // anode direction charge integration width
    Int_t    timeWindow;  // time direction charge integration width
    Int_t    jamin,jamax; // anode charge integration window
    Int_t    jtmin,jtmax; // time charge integration window
    Int_t    ndiv;        // Anode window division factor.
    Int_t    nsplit;      // the number of splits in anode and time windows==1.
    Int_t    nOfSplits;   // number of times track length is split into
    Float_t  nOfSplitsF;  // Floating point version of nOfSplits.
    Float_t  kkF;         // Floating point version of loop index kk.
    Float_t  pathInSDD; // Track length in SDD.
    Float_t  drPath; // average position of track in detector. in microns
    Float_t  drTime; // Drift time
    Float_t  nmul;   // drift time window multiplication factor.
    Float_t  avDrft;  // x position of path length segment in cm.
    Float_t  avAnode; // Anode for path length segment in Anode number (float)
    Float_t  xAnode;  // Floating point anode number.
    Float_t  driftPath; // avDrft in microns.
    Float_t  width;     // width of signal at anodes.
    Double_t  depEnergy; // Energy deposited in this GEANT step.
    Double_t  xL[3],dxL[3]; // local hit coordinates and diff.
    Double_t sigA; // sigma of signal at anode.
    Double_t sigT; // sigma in time/drift direction for track segment
    Double_t aStep,aConst; // sub-pixel size and offset anode
    Double_t tStep,tConst; // sub-pixel size and offset time
    Double_t amplitude; // signal amplitude for track segment in nanoAmpere
    Double_t chargeloss; // charge loss for track segment.
    Double_t anodeAmplitude; // signal amplitude in anode direction
    Double_t aExpo;          // exponent of Gaussian anode direction
    Double_t timeAmplitude;  // signal amplitude in time direction
    Double_t tExpo;          // exponent of Gaussian time direction
//  Double_t tof;            // Time of flight in ns of this step.    

    for(ii=0; ii<nhits; ii++) {
	if(!mod->LineSegmentL(ii,xL[0],dxL[0],xL[1],dxL[1],xL[2],dxL[2],
			      depEnergy,itrack)) continue;
	depEnergy  *= kconv;
	hitDetector = mod->GetDet();
	//tof         = 1.E+09*(mod->GetHit(ii)->GetTOF()); // tof in ns.
	//if(tof>sddLength/driftSpeed) continue; // hit happed too late.

	// scale path to simulate a perpendicular track
	// continue if the particle did not lose energy
	// passing through detector
	if (!depEnergy) {
	    Warning("HitsToAnalogDigits", 
		    "This particle has passed without losing energy!");
	    continue;
	} // end if !depEnergy

	pathInSDD = TMath::Sqrt(dxL[0]*dxL[0]+dxL[1]*dxL[1]+dxL[2]*dxL[2]);

	if (fFlag && pathInSDD) { depEnergy *= (0.03/pathInSDD); }
	drPath = 10000.*(dxL[0]+2.*xL[0])*0.5;
	if(drPath < 0) drPath = -drPath;
	drPath = sddLength-drPath;
	if(drPath < 0) {
	    Warning("HitsToAnalogDigits","negative drift path %e",drPath);
	    continue;
	} // end if drPath < 0

	// Compute number of segments to brake step path into
	drTime = drPath/driftSpeed;  //   Drift Time
	sigA   = TMath::Sqrt(2.*dfCoeff*drTime+s1*s1);// Sigma along the anodes
	// calcuate the number of time the path length should be split into.
	nOfSplits = (Int_t) (1. + 10000.*pathInSDD/sigA);
	if(fFlag) nOfSplits = 1;

	// loop over path segments, init. some variables.
	depEnergy /= nOfSplits;
	nOfSplitsF = (Float_t) nOfSplits;
	for(kk=0;kk<nOfSplits;kk++) { // loop over path segments
	    kkF       = (Float_t) kk + 0.5;
	    avDrft    = xL[0]+dxL[0]*kkF/nOfSplitsF;
	    avAnode   = xL[2]+dxL[2]*kkF/nOfSplitsF;
	    driftPath = 10000.*avDrft;

	    iWing = 2;  // Assume wing is 2
	    if(driftPath < 0) { // if wing is not 2 it is 1.
		iWing     = 1;
		driftPath = -driftPath;
	    } // end if driftPath < 0
	    driftPath = sddLength-driftPath;
	    detector  = 2*(hitDetector-1) + iWing;
	    if(driftPath < 0) {
		Warning("HitsToAnalogDigits","Warning: negative drift path %e",
			driftPath);
		continue;
	    } // end if driftPath < 0

	    //   Drift Time
	    drTime     = driftPath/driftSpeed; // drift time for segment.
	    timeSample = (Int_t) (fScaleSize*drTime/timeStep + 1);
	    // compute time Sample including tof information. The tof only 
	    // effects the time of the signal is recoreded and not the
	    // the defusion.
	    // timeSample = (Int_t) (fScaleSize*(drTime+tof)/timeStep + 1);
	    if(timeSample > fScaleSize*fMaxNofSamples) {
		Warning("HItsToAnalogDigits","Wrong Time Sample: %e",
			timeSample);
		continue;
	    } // end if timeSample > fScaleSize*fMaxNoofSamples

	    //   Anode
	    xAnode = 10000.*(avAnode)/anodePitch + nofAnodes/2;  // +1?
	    if(xAnode*anodePitch > sddWidth || xAnode*anodePitch < 0.) 
	                  Warning("HitsToAnalogDigits","Z = %e",
				  xAnode*anodePitch);
	    iAnode = (Int_t) (1.+xAnode); // xAnode?
	    if(iAnode < 1 || iAnode > nofAnodes) {
		Warning("HitToAnalogDigits","Wrong iAnode: %d",iAnode);
		continue;
	    } // end if iAnode < 1 || iAnode > nofAnodes

	    // store straight away the particle position in the array
	    // of particles and take idhit=ii only when part is entering (this
	    // requires FillModules() in the macro for analysis) :
    
	    // Sigma along the anodes for track segment.
	    sigA       = TMath::Sqrt(2.*dfCoeff*drTime+s1*s1);
	    sigT       = sigA/driftSpeed;
	    // Peak amplitude in nanoAmpere
	    amplitude  = fScaleSize*160.*depEnergy/
		                 (timeStep*eVpairs*2.*acos(-1.)*sigT*sigA);
	    amplitude *= timeStep/25.; // WARNING!!!!! Amplitude scaling to 
	                               // account for clock variations 
                                       // (reference value: 40 MHz)
	    chargeloss = 1.-cHloss*driftPath/1000;
	    amplitude *= chargeloss;
	    width  = 2.*nsigma/(nlookups-1);
	    // Spread the charge 
	    // Pixel index
	    ndiv = 2;
	    nmul = 3.; 
	    if(drTime > 1200.) { 
		ndiv = 4;
		nmul = 1.5;
	    } // end if drTime > 1200.
	    // Sub-pixel index
	    nsplit = 4; // hard-wired //nsplit=4;nsplit = (nsplit+1)/2*2;
	    // Sub-pixel size see computation of aExpo and tExpo.
	    aStep  = anodePitch/(nsplit*fScaleSize*sigA);
	    aConst = xAnode*anodePitch/sigA;
	    tStep  = timeStep/(nsplit*fScaleSize*sigT);
	    tConst = drTime/sigT;
	    // Define SDD window corresponding to the hit
	    anodeWindow = (Int_t)(fScaleSize*nsigma*sigA/anodePitch+1);
	    timeWindow  = (Int_t) (fScaleSize*nsigma*sigT/timeStep+1.);
	    jamin = (iAnode - anodeWindow/ndiv - 1)*fScaleSize*nsplit +1;
	    jamax = (iAnode + anodeWindow/ndiv)*fScaleSize*nsplit;
	    if(jamin <= 0) jamin = 1;
	    if(jamax > fScaleSize*nofAnodes*nsplit) 
		                         jamax = fScaleSize*nofAnodes*nsplit;
	    // jtmin and jtmax are Hard-wired
	    jtmin = (Int_t)(timeSample-timeWindow*nmul-1)*nsplit+1;
	    jtmax = (Int_t)(timeSample+timeWindow*nmul)*nsplit;
	    if(jtmin <= 0) jtmin = 1;
	    if(jtmax > fScaleSize*fMaxNofSamples*nsplit) 
		                      jtmax = fScaleSize*fMaxNofSamples*nsplit;
	    // Spread the charge in the anode-time window
	    for(ka=jamin; ka <=jamax; ka++) {
		ia = (ka-1)/(fScaleSize*nsplit) + 1;
		if(ia <= 0) {
		    Warning("HitsToAnalogDigits","ia < 1: ");
		    continue;
		} // end if
		if(ia > nofAnodes) ia = nofAnodes;
		aExpo     = (aStep*(ka-0.5)-aConst);
		if(TMath::Abs(aExpo) > nsigma)  anodeAmplitude = 0.;
		else {
		    dummy          = (Int_t) ((aExpo+nsigma)/width);
		    anodeAmplitude = amplitude*fResponse->GausLookUp(dummy);
		} // end if TMath::Abs(aEspo) > nsigma
		// index starts from 0
		index = ((detector+1)%2)*nofAnodes+ia-1;
		if(anodeAmplitude) for(kt=jtmin; kt<=jtmax; kt++) {
		    it = (kt-1)/nsplit+1;  // it starts from 1
		    if(it<=0){
			Warning("HitsToAnalogDigits","it < 1:");
			continue;
		    } // end if 
		    if(it>fScaleSize*fMaxNofSamples)
			                        it = fScaleSize*fMaxNofSamples;
		    tExpo    = (tStep*(kt-0.5)-tConst);
		    if(TMath::Abs(tExpo) > nsigma) timeAmplitude = 0.;
		    else {
			dummy         = (Int_t) ((tExpo+nsigma)/width);
			timeAmplitude = anodeAmplitude*
			                fResponse->GausLookUp(dummy);
		    } // end if TMath::Abs(tExpo) > nsigma
		    // build the list of digits for this module	
		    arg[0]         = index;
		    arg[1]         = it;
		    arg[2]         = itrack; // track number
		    arg[3]         = ii-1; // hit number.
		    timeAmplitude *= norm;
		    timeAmplitude *= 10;
		    ListOfFiredCells(arg,timeAmplitude,alst,padr);
		    pList->AddSignal(index,it,itrack,ii-1,
				     mod->GetIndex(),timeAmplitude);
		} // end if anodeAmplitude and loop over time in window
	    } // loop over anodes in window
	} // end loop over "sub-hits"
    } // end loop over hits
}
//______________________________________________________________________
void AliITSsimulationSDD::ListOfFiredCells(Int_t *arg,Double_t timeAmplitude,
                                          TObjArray *alist,TClonesArray *padr){
    // Returns the list of "fired" cells.

    Int_t index     = arg[0];
    Int_t ik        = arg[1];
    Int_t idtrack   = arg[2];
    Int_t idhit     = arg[3];
    Int_t counter   = arg[4];
    Int_t countadr  = arg[5];
    Double_t charge = timeAmplitude;
    charge += fHitMap2->GetSignal(index,ik-1);
    fHitMap2->SetHit(index, ik-1, charge);

    Int_t digits[3];
    Int_t it = (Int_t)((ik-1)/fScaleSize);
    digits[0] = index;
    digits[1] = it;
    digits[2] = (Int_t)timeAmplitude;
    Float_t phys;
    if (idtrack >= 0) phys = (Float_t)timeAmplitude;
    else phys = 0;

    Double_t cellcharge = 0.;
    AliITSTransientDigit* pdigit;
    // build the list of fired cells and update the info
    if (!fHitMap1->TestHit(index, it)) {
	new((*padr)[countadr++]) TVector(3);
	TVector &trinfo=*((TVector*) (*padr)[countadr-1]);
	trinfo(0) = (Float_t)idtrack;
	trinfo(1) = (Float_t)idhit;
	trinfo(2) = (Float_t)timeAmplitude;

	alist->AddAtAndExpand(new AliITSTransientDigit(phys,digits),counter);
	fHitMap1->SetHit(index, it, counter);
	counter++;
	pdigit=(AliITSTransientDigit*)alist->At(alist->GetLast());
	// list of tracks
	TObjArray *trlist=(TObjArray*)pdigit->TrackList();
	trlist->Add(&trinfo);
    } else {
	pdigit = (AliITSTransientDigit*) fHitMap1->GetHit(index, it);
	for(Int_t kk=0;kk<fScaleSize;kk++) {
	    cellcharge += fHitMap2->GetSignal(index,fScaleSize*it+kk);
	}  // end for kk
	// update charge
	(*pdigit).fSignal = (Int_t)cellcharge;
	(*pdigit).fPhysics += phys;			
	// update list of tracks
	TObjArray* trlist = (TObjArray*)pdigit->TrackList();
	Int_t lastentry = trlist->GetLast();
	TVector *ptrkp = (TVector*)trlist->At(lastentry);
	TVector &trinfo = *ptrkp;
	Int_t lasttrack = Int_t(trinfo(0));
	Float_t lastcharge=(trinfo(2));
	if (lasttrack==idtrack ) {
	    lastcharge += (Float_t)timeAmplitude;
	    trlist->RemoveAt(lastentry);
	    trinfo(0) = lasttrack;
	    trinfo(1) = idhit;
	    trinfo(2) = lastcharge;
	    trlist->AddAt(&trinfo,lastentry);
	} else {		  
	    new((*padr)[countadr++]) TVector(3);
	    TVector &trinfo=*((TVector*) (*padr)[countadr-1]);
	    trinfo(0) = (Float_t)idtrack;
	    trinfo(1) = (Float_t)idhit;
	    trinfo(2) = (Float_t)timeAmplitude;
	    trlist->Add(&trinfo);
	} // end if lasttrack==idtrack

#ifdef print
	// check the track list - debugging
	Int_t trk[20], htrk[20];
	Float_t chtrk[20];  
	Int_t nptracks = trlist->GetEntriesFast();
	if (nptracks > 2) {
	    Int_t tr;
	    for (tr=0;tr<nptracks;tr++) {
		TVector *pptrkp = (TVector*)trlist->At(tr);
		TVector &pptrk  = *pptrkp;
		trk[tr]   = Int_t(pptrk(0));
		htrk[tr]  = Int_t(pptrk(1));
		chtrk[tr] = (pptrk(2));
		cout << "nptracks "<<nptracks << endl;
	    } // end for tr
	} // end if nptracks
#endif
    } //  end if pdigit

    // update counter and countadr for next call.
    arg[4] = counter;
    arg[5] = countadr;
}
//____________________________________________

void AliITSsimulationSDD::AddDigit(Int_t i, Int_t j, Int_t signal){
    // Adds a Digit.
    // tag with -1 signals coming from background tracks
    // tag with -2 signals coming from pure electronic noise

    Int_t digits[3], tracks[3], hits[3];
    Float_t phys, charges[3];

    Int_t trk[20], htrk[20];
    Float_t chtrk[20];  

    Bool_t do10to8=fResponse->Do10to8();

    if(do10to8) signal=Convert8to10(signal); 
    AliITSTransientDigit *obj = (AliITSTransientDigit*)fHitMap1->GetHit(i,j);
    digits[0] = i;
    digits[1] = j;
    digits[2] = signal;
    if (!obj) {
        phys=0;
        Int_t k;
        for (k=0;k<3;k++) {
	    tracks[k]=-2;
	    charges[k]=0;
	    hits[k]=-1;
	} // end for k
        fITS->AddSimDigit(1,phys,digits,tracks,hits,charges); 
    } else {
	phys=obj->fPhysics;
	TObjArray* trlist=(TObjArray*)obj->TrackList();
	Int_t nptracks=trlist->GetEntriesFast();
	if (nptracks > 20) {
	    Warning("AddDigit","nptracks=%d > 20 nptracks set to 20",nptracks);
	    nptracks=20;
	} // end if nptracks > 20
	Int_t tr;
	for (tr=0;tr<nptracks;tr++) {
	    TVector &pp  =*((TVector*)trlist->At(tr));
	    trk[tr]=Int_t(pp(0));
	    htrk[tr]=Int_t(pp(1));
	    chtrk[tr]=(pp(2));
	} // end for tr
	if (nptracks > 1) {
	    SortTracks(trk,chtrk,htrk,nptracks);
	} // end if nptracks > 1
	Int_t i;
	if (nptracks < 3 ) {
	    for (i=0; i<nptracks; i++) {
		tracks[i]=trk[i];
		charges[i]=chtrk[i];
		hits[i]=htrk[i];
	    } // end for i
	    for (i=nptracks; i<3; i++) {
		tracks[i]=-3;
		hits[i]=-1;
		charges[i]=0;
	    } // end for i
	} else {
	    for (i=0; i<3; i++) {
		tracks[i]=trk[i];
		charges[i]=chtrk[i];
		hits[i]=htrk[i];
	    } // end for i
	} // end if/else nptracks < 3

	fITS->AddSimDigit(1,phys,digits,tracks,hits,charges); 
 
    } // end if/else !obj
}
//______________________________________________________________________
void AliITSsimulationSDD::SortTracks(Int_t *tracks,Float_t *charges,
				     Int_t *hits,Int_t ntr){
    // Sort the list of tracks contributing to a given digit
    // Only the 3 most significant tracks are acctually sorted
    //  Loop over signals, only 3 times

    Float_t qmax;
    Int_t   jmax;
    Int_t   idx[3]  = {-3,-3,-3};
    Float_t jch[3]  = {-3,-3,-3};
    Int_t   jtr[3]  = {-3,-3,-3};
    Int_t   jhit[3] = {-3,-3,-3};
    Int_t   i,j,imax;

    if (ntr<3) imax = ntr;
    else imax = 3;
    for(i=0;i<imax;i++){
	qmax = 0;
	jmax = 0;
	for(j=0;j<ntr;j++){
	    if((i == 1 && j == idx[i-1] )
	       ||(i == 2 && (j == idx[i-1] || j == idx[i-2]))) continue;
	    if(charges[j] > qmax) {
		qmax = charges[j];
		jmax=j;
	    } // end if charges[j]>qmax
	} // end for j
	if(qmax > 0) {
	    idx[i]  = jmax;
	    jch[i]  = charges[jmax]; 
	    jtr[i]  = tracks[jmax]; 
	    jhit[i] = hits[jmax]; 
	} // end if qmax > 0
    } // end for i

    for(i=0;i<3;i++){
	if (jtr[i] == -3) {
	    charges[i] = 0;
	    tracks[i]  = -3;
	    hits[i]    = -1;
	} else {
	    charges[i] = jch[i];
	    tracks[i]  = jtr[i];
	    hits[i]    = jhit[i];
	} // end if jtr[i] == -3
    } // end for i
}
//______________________________________________________________________
void AliITSsimulationSDD::ChargeToSignal() {
    // add baseline, noise, electronics and ADC saturation effects

    char opt1[20], opt2[20];
    fResponse->ParamOptions(opt1,opt2);
    char *read = strstr(opt1,"file");
    Float_t baseline, noise; 

    if (read) {
	static Bool_t readfile=kTRUE;
	//read baseline and noise from file
	if (readfile) ReadBaseline();
	readfile=kFALSE;
    } else fResponse->GetNoiseParam(noise,baseline);

    Float_t contrib=0;
    Int_t i,k,kk;
    Float_t maxadc = fResponse->MaxAdc();    
    if(!fDoFFT) {
	for (i=0;i<fNofMaps;i++) {
	    if (read && i<fNofMaps) GetAnodeBaseline(i,baseline,noise);
	    for(k=0; k<fScaleSize*fMaxNofSamples; k++) {
		fInZR[k]  = fHitMap2->GetSignal(i,k);
		contrib   = (baseline + noise*gRandom->Gaus());
		fInZR[k] += contrib;
	    } // end for k
	    for(k=0; k<fMaxNofSamples; k++) {
		Double_t newcont = 0.;
		Double_t maxcont = 0.;
		for(kk=0;kk<fScaleSize;kk++) {
		    newcont = fInZR[fScaleSize*k+kk];
		    if(newcont > maxcont) maxcont = newcont;
		} // end for kk
		newcont = maxcont;
		if (newcont >= maxadc) newcont = maxadc -1;
		if(newcont >= baseline){
		    Warning("","newcont=%d>=baseline=%d",newcont,baseline);
		} // end if
		// back to analog: ?
		fHitMap2->SetHit(i,k,newcont);
	    }  // end for k
	} // end for i loop over anodes
	return;
    } // end if DoFFT

    for (i=0;i<fNofMaps;i++) {
	if  (read && i<fNofMaps) GetAnodeBaseline(i,baseline,noise);
	for(k=0; k<fScaleSize*fMaxNofSamples; k++) {
	    fInZR[k]  = fHitMap2->GetSignal(i,k);
	    contrib   = (baseline + noise*gRandom->Gaus());
	    fInZR[k] += contrib;
	    fInZI[k]  = 0.;
	} // end for k
	FastFourierTransform(fElectronics,&fInZR[0],&fInZI[0],1);
	for(k=0; k<fScaleSize*fMaxNofSamples; k++) {
	    Double_t rw = fElectronics->GetTraFunReal(k);
	    Double_t iw = fElectronics->GetTraFunImag(k);
	    fOutZR[k]   = fInZR[k]*rw - fInZI[k]*iw;
	    fOutZI[k]   = fInZR[k]*iw + fInZI[k]*rw;
	} // end for k
	FastFourierTransform(fElectronics,&fOutZR[0],&fOutZI[0],-1);
	for(k=0; k<fMaxNofSamples; k++) {
	    Double_t newcont1 = 0.;
	    Double_t maxcont1 = 0.;
	    for(kk=0;kk<fScaleSize;kk++) {
		newcont1 = fOutZR[fScaleSize*k+kk];
		if(newcont1 > maxcont1) maxcont1 = newcont1;
	    } // end for kk
	    newcont1 = maxcont1;
	    if (newcont1 >= maxadc) newcont1 = maxadc -1;
	    fHitMap2->SetHit(i,k,newcont1);
	} // end for k
    } // end for i loop over anodes
  return;
}
//______________________________________________________________________
void AliITSsimulationSDD::GetAnodeBaseline(Int_t i,Float_t &baseline,
                                           Float_t &noise){
    // Returns the Baseline for a particular anode.
    baseline = fBaseline[i];
    noise    = fNoise[i];
}
//______________________________________________________________________
void AliITSsimulationSDD::CompressionParam(Int_t i,Int_t &db,Int_t &tl,
                                           Int_t &th){
    // Returns the compression alogirthm parameters
    Int_t size = fD.GetSize();
    if (size > 2 ) {
	db=fD[i]; tl=fT1[i]; th=fT2[i];
    } else {
	if (size <= 2 && i>=fNofMaps/2) {
	    db=fD[1]; tl=fT1[1]; th=fT2[1];
	} else {
	    db=fD[0]; tl=fT1[0]; th=fT2[0];
	} // end if size <=2 && i>=fNofMaps/2
    } // end if size >2
}
//______________________________________________________________________
void AliITSsimulationSDD::CompressionParam(Int_t i,Int_t &db,Int_t &tl){
    // returns the compression alogirthm parameters
    Int_t size = fD.GetSize();

    if (size > 2 ) {
	db=fD[i]; tl=fT1[i];
    } else {
	if (size <= 2 && i>=fNofMaps/2) {
	    db=fD[1]; tl=fT1[1]; 
	} else {
	    db=fD[0]; tl=fT1[0]; 
	} // end if size <=2 && i>=fNofMaps/2
    } // end if size > 2
}
//______________________________________________________________________
void AliITSsimulationSDD::SetCompressParam(){
    // Sets the compression alogirthm parameters  
    Int_t cp[8],i;

    fResponse->GiveCompressParam(cp);
    for (i=0; i<2; i++) {
	fD[i]   = cp[i];
	fT1[i]  = cp[i+2];
	fT2[i]  = cp[i+4];
	fTol[i] = cp[i+6];
    } // end for i
}
//______________________________________________________________________
void AliITSsimulationSDD::ReadBaseline(){
    // read baseline and noise from file - either a .root file and in this
    // case data should be organised in a tree with one entry for each
    // module => reading should be done accordingly
    // or a classic file and do smth. like this:
    // Read baselines and noise for SDD

    Int_t na,pos;
    Float_t bl,n;
    char input[100], base[100], param[100];
    char *filtmp;

    fResponse->Filenames(input,base,param);
    fFileName=base;
//
    filtmp = gSystem->ExpandPathName(fFileName.Data());
    FILE *bline = fopen(filtmp,"r");
    na = 0;

    if(bline) {
	while(fscanf(bline,"%d %f %f",&pos, &bl, &n) != EOF) {
	    if (pos != na+1) {
		Error("ReadBaseline","Anode number not in increasing order!",
		      filtmp);
		exit(1);
	    } // end if pos != na+1
	    fBaseline[na]=bl;
	    fNoise[na]=n;
	    na++;
	} // end while
    } else {
	Error("ReadBaseline"," THE BASELINE FILE %s DOES NOT EXIST !",filtmp);
	exit(1);
    } // end if(bline)

    fclose(bline);
    delete [] filtmp;
}
//______________________________________________________________________
Int_t AliITSsimulationSDD::Convert10to8(Int_t signal) const {
    // To the 10 to 8 bit lossive compression.
    // code from Davide C. and Albert W.

    if (signal < 128)  return signal;
    if (signal < 256)  return (128+((signal-128)>>1));
    if (signal < 512)  return (192+((signal-256)>>3));
    if (signal < 1024) return (224+((signal-512)>>4));
    return 0;
}
//______________________________________________________________________
Int_t AliITSsimulationSDD::Convert8to10(Int_t signal) const {
    // Undo the lossive 10 to 8 bit compression.
    // code from Davide C. and Albert W.
    if (signal < 0 || signal > 255) {
	Warning("Convert8to10","out of range signal=%d",signal);
	return 0;
    } // end if signal <0 || signal >255

    if (signal < 128) return signal;
    if (signal < 192) {
	if (TMath::Odd(signal)) return (128+((signal-128)<<1));
	else  return (128+((signal-128)<<1)+1);
    } // end if signal < 192
    if (signal < 224) {
	if (TMath::Odd(signal)) return (256+((signal-192)<<3)+3);
	else  return (256+((signal-192)<<3)+4);
    } // end if signal < 224
    if (TMath::Odd(signal)) return (512+((signal-224)<<4)+7);
    else  return (512+((signal-224)<<4)+7);
    return 0;
}
//______________________________________________________________________
AliITSMap*   AliITSsimulationSDD::HitMap(Int_t i){
    //Return the correct map.

    return ((i==0)? fHitMap1 : fHitMap2);
}
//______________________________________________________________________
void AliITSsimulationSDD::ZeroSuppression(const char *option) {
    // perform the zero suppresion

    if (strstr(option,"2D")) {
	//Init2D();              // activate if param change module by module
	Compress2D();
    } else if (strstr(option,"1D")) {
	//Init1D();              // activate if param change module by module
	Compress1D();  
    } else StoreAllDigits();
}
//______________________________________________________________________
void AliITSsimulationSDD::Init2D(){
    // read in and prepare arrays: fD, fT1, fT2
    //                         savemu[nanodes], savesigma[nanodes] 
    // read baseline and noise from file - either a .root file and in this
    // case data should be organised in a tree with one entry for each
    // module => reading should be done accordingly
    // or a classic file and do smth. like this ( code from Davide C. and
    // Albert W.) :
    // Read 2D zero-suppression parameters for SDD

    if (!strstr(fParam,"file")) return;

    Int_t na,pos,tempTh;
    Float_t mu,sigma;
    Float_t *savemu    = new Float_t [fNofMaps];
    Float_t *savesigma = new Float_t [fNofMaps];
    char input[100],basel[100],par[100];
    char *filtmp;
    Int_t minval = fResponse->MinVal();

    fResponse->Filenames(input,basel,par);
    fFileName = par;
//
    filtmp = gSystem->ExpandPathName(fFileName.Data());
    FILE *param = fopen(filtmp,"r");
    na = 0;

    if(param) {
	while(fscanf(param,"%d %f %f",&pos, &mu, &sigma) != EOF) {
	    if (pos != na+1) {
		Error("Init2D","Anode number not in increasing order!",filtmp);
		exit(1);
	    } // end if pos != na+1
	    savemu[na] = mu;
          savesigma[na] = sigma;
          if ((2.*sigma) < mu) {
              fD[na] = (Int_t)floor(mu - 2.0*sigma + 0.5);
              mu = 2.0 * sigma;
	  } else fD[na] = 0;
          tempTh = (Int_t)floor(mu+2.25*sigma+0.5) - minval;
          if (tempTh < 0) tempTh=0;
          fT1[na] = tempTh;
          tempTh = (Int_t)floor(mu+3.0*sigma+0.5) - minval;
          if (tempTh < 0) tempTh=0;
          fT2[na] = tempTh;
          na++;
	} // end while
    } else {
	Error("Init2D","THE FILE %s DOES NOT EXIST !",filtmp);
	exit(1);
    } // end if(param)

    fclose(param);
    delete [] filtmp;
    delete [] savemu;
    delete [] savesigma;
}
//______________________________________________________________________
void AliITSsimulationSDD::Compress2D(){
    // simple ITS cluster finder -- online zero-suppression conditions

    Int_t db,tl,th;  
    Int_t minval   = fResponse->MinVal();
    Bool_t write   = fResponse->OutputOption();   
    Bool_t do10to8 = fResponse->Do10to8();
    Int_t nz, nl, nh, low, i, j; 

    for (i=0; i<fNofMaps; i++) {
        CompressionParam(i,db,tl,th);
        nz  = 0; 
        nl  = 0;
        nh  = 0;
        low = 0;
	for (j=0; j<fMaxNofSamples; j++) {
	    Int_t signal=(Int_t)(fHitMap2->GetSignal(i,j));
	    signal -= db; // if baseline eq. is done here
            if (signal <= 0) {nz++; continue;}
	    if ((signal - tl) < minval) low++;
            if ((signal - th) >= minval) {
	        nh++;
		Bool_t cond=kTRUE;
		FindCluster(i,j,signal,minval,cond);
		if(cond && j &&
		   ((TMath::Abs(fHitMap2->GetSignal(i,j-1))-th)>=minval)){
		    if(do10to8) signal = Convert10to8(signal);
		    AddDigit(i,j,signal);
		} // end if cond&&j&&()
	    } else if ((signal - tl) >= minval) nl++;
	} // end for j loop time samples
	if (write) TreeB()->Fill(nz,nl,nh,low,i+1);
    } //end for i loop anodes

    char hname[30];
    if (write) {
	sprintf(hname,"TNtuple%d_%d",fModule,fEvent);
	TreeB()->Write(hname);
	// reset tree
        TreeB()->Reset();
    } // end if write
}
//______________________________________________________________________
void  AliITSsimulationSDD::FindCluster(Int_t i,Int_t j,Int_t signal,
                                       Int_t minval,Bool_t &cond){
    // Find clusters according to the online 2D zero-suppression algorithm
    Bool_t do10to8 = fResponse->Do10to8();
    Bool_t high    = kFALSE;

    fHitMap2->FlagHit(i,j);
//
//  check the online zero-suppression conditions
//  
    const Int_t kMaxNeighbours = 4;
    Int_t nn;
    Int_t dbx,tlx,thx;  
    Int_t xList[kMaxNeighbours], yList[kMaxNeighbours];
    fSegmentation->Neighbours(i,j,&nn,xList,yList);
    Int_t in,ix,iy,qns;
    for (in=0; in<nn; in++) {
	ix=xList[in];
        iy=yList[in];
        if (fHitMap2->TestHit(ix,iy)==kUnused) {
	    CompressionParam(ix,dbx,tlx,thx);
	    Int_t qn = (Int_t)(fHitMap2->GetSignal(ix,iy));
	    qn -= dbx; // if baseline eq. is done here
	    if ((qn-tlx) < minval) {
		fHitMap2->FlagHit(ix,iy);
		continue;
	    } else {
		if ((qn - thx) >= minval) high=kTRUE;
		if (cond) {
		    if(do10to8) signal = Convert10to8(signal);
		    AddDigit(i,j,signal);
		} // end if cond
		if(do10to8) qns = Convert10to8(qn);
		else qns=qn;
		if (!high) AddDigit(ix,iy,qns);
		cond=kFALSE;
		if(!high) fHitMap2->FlagHit(ix,iy);
	    } // end if qn-tlx < minval
	} // end if  TestHit
    } // end for in loop over neighbours
}
//______________________________________________________________________
void AliITSsimulationSDD::Init1D(){
    // this is just a copy-paste of input taken from 2D algo
    // Torino people should give input
    // Read 1D zero-suppression parameters for SDD

    if (!strstr(fParam,"file")) return;

    Int_t na,pos,tempTh;
    Float_t mu,sigma;
    Float_t *savemu    = new Float_t [fNofMaps];
    Float_t *savesigma = new Float_t [fNofMaps];
    char input[100],basel[100],par[100];
    char *filtmp;
    Int_t minval = fResponse->MinVal();

    fResponse->Filenames(input,basel,par);
    fFileName=par;

//  set first the disable and tol param
    SetCompressParam();
//
    filtmp = gSystem->ExpandPathName(fFileName.Data());
    FILE *param = fopen(filtmp,"r");
    na = 0;

    if (param) {
	fscanf(param,"%d %d %d %d ", &fT2[0], &fT2[1], &fTol[0], &fTol[1]);
	while(fscanf(param,"%d %f %f",&pos, &mu, &sigma) != EOF) {
	    if (pos != na+1) {
		Error("Init1D","Anode number not in increasing order!",filtmp);
		exit(1);
	    } // end if pos != na+1
	    savemu[na]=mu;
	    savesigma[na]=sigma;
	    if ((2.*sigma) < mu) {
		fD[na] = (Int_t)floor(mu - 2.0*sigma + 0.5);
		mu = 2.0 * sigma;
	    } else fD[na] = 0;
	    tempTh = (Int_t)floor(mu+2.25*sigma+0.5) - minval;
	    if (tempTh < 0) tempTh=0;
	    fT1[na] = tempTh;
	    na++;
	} // end while
    } else {
	Error("Init1D","THE FILE %s DOES NOT EXIST !",filtmp);
	exit(1);
    } // end if(param)

    fclose(param);
    delete [] filtmp;
    delete [] savemu;
    delete [] savesigma;
} 
//______________________________________________________________________
void AliITSsimulationSDD::Compress1D(){
    // 1D zero-suppression algorithm (from Gianluca A.)
    Int_t    dis,tol,thres,decr,diff;
    UChar_t *str=fStream->Stream();
    Int_t    counter=0;
    Bool_t   do10to8=fResponse->Do10to8();
    Int_t    last=0;
    Int_t    k,i,j;

    for (k=0; k<2; k++) {
	tol = Tolerance(k);
	dis = Disable(k);  
	for (i=0; i<fNofMaps/2; i++) {
	    Bool_t firstSignal=kTRUE;
	    Int_t idx=i+k*fNofMaps/2;
	    CompressionParam(idx,decr,thres); 
	    for (j=0; j<fMaxNofSamples; j++) {
		Int_t signal=(Int_t)(fHitMap2->GetSignal(idx,j));
		signal -= decr;  // if baseline eq.
		if(do10to8) signal = Convert10to8(signal);
		if (signal <= thres) {
		    signal=0;
		    diff=128; 
		    last=0; 
		    // write diff in the buffer for HuffT
		    str[counter]=(UChar_t)diff;
		    counter++;
		    continue;
		} // end if signal <= thres
		diff=signal-last;
		if (diff > 127) diff=127;
		if (diff < -128) diff=-128;
		if (signal < dis) {
		    // tol has changed to 8 possible cases ? - one can write
		    // this if(TMath::Abs(diff)<tol) ... else ...
		    if(TMath::Abs(diff)<tol) diff=0;
		    // or keep it as it was before
		    /*
                    if (tol==1 && (diff >= -2 && diff <= 1)) diff=0;
                    if (tol==2 && (diff >= -4 && diff <= 3)) diff=0;
                    if (tol==3 && (diff >= -16 && diff <= 15)) diff=0;
		    */
                    AddDigit(idx,j,last+diff);
		} else {
		    AddDigit(idx,j,signal);
		} // end if singal < dis
		diff += 128;
		// write diff in the buffer used to compute Huffman tables
		if (firstSignal) str[counter]=(UChar_t)signal;
		else str[counter]=(UChar_t)diff;
		counter++;
		last=signal;
		firstSignal=kFALSE;
	    } // end for j loop time samples
	} // end for i loop anodes  one half of detector 
    } //  end for k

    // check
    fStream->CheckCount(counter);

    // open file and write out the stream of diff's
    static Bool_t open=kTRUE;
    static TFile *outFile;
    Bool_t write = fResponse->OutputOption();
 
    if (write ) {
	if(open) {
	    SetFileName("stream.root");
	    cout<<"filename "<<fFileName<<endl;
	    outFile=new TFile(fFileName,"recreate");
	    cout<<"I have opened "<<fFileName<<" file "<<endl;
	} // end if open
	open = kFALSE;
	outFile->cd();
        fStream->Write();
    }  // endif write	

    fStream->ClearStream();

    // back to galice.root file

    TTree *fAli=gAlice->TreeK();
    TFile *file = 0;

    if (fAli) file =fAli->GetCurrentFile();
    file->cd();
}
//______________________________________________________________________
void AliITSsimulationSDD::StoreAllDigits(){
    // if non-zero-suppressed data
    Bool_t do10to8 = fResponse->Do10to8();
    Int_t i, j, digits[3];

    for (i=0; i<fNofMaps; i++) {
        for (j=0; j<fMaxNofSamples; j++) {
	    Int_t signal=(Int_t)(fHitMap2->GetSignal(i,j));
	    if(do10to8) signal = Convert10to8(signal);
	    if(do10to8) signal = Convert8to10(signal); 
	    digits[0] = i;
	    digits[1] = j;
	    digits[2] = signal;
	    fITS->AddRealDigit(1,digits);
	} // end for j
    } // end for i
} 
//______________________________________________________________________
void AliITSsimulationSDD::CreateHistograms(Int_t scale){
    // Creates histograms of maps for debugging
    Int_t i;

      fHis=new TObjArray(fNofMaps);
      for (i=0;i<fNofMaps;i++) {
	   TString sddName("sdd_");
	   Char_t candNum[4];
	   sprintf(candNum,"%d",i+1);
	   sddName.Append(candNum);
	   fHis->AddAt(new TH1F(sddName.Data(),"SDD maps",scale*fMaxNofSamples,
				0.,(Float_t) scale*fMaxNofSamples), i);
      } // end for i
}
//______________________________________________________________________
void AliITSsimulationSDD::FillHistograms(){
    // fill 1D histograms from map

    if (!fHis) return;

    for( Int_t i=0; i<fNofMaps; i++) {
	TH1F *hist =(TH1F *)fHis->UncheckedAt(i);
	Int_t nsamples = hist->GetNbinsX();
	for( Int_t j=0; j<nsamples; j++) {
	    Double_t signal=fHitMap2->GetSignal(i,j);
	    hist->Fill((Float_t)j,signal);
	} // end for j
    } // end for i
}
//______________________________________________________________________
void AliITSsimulationSDD::ResetHistograms(){
    // Reset histograms for this detector
    Int_t i;

    for (i=0;i<fNofMaps;i++ ) {
	if (fHis->At(i))    ((TH1F*)fHis->At(i))->Reset();
    } // end for i
}
//______________________________________________________________________
TH1F *AliITSsimulationSDD::GetAnode(Int_t wing, Int_t anode) { 
    // Fills a histogram from a give anode.  

    if (!fHis) return 0;

    if(wing <=0 || wing > 2) {
	Warning("GetAnode","Wrong wing number: %d",wing);
	return NULL;
    } // end if wing <=0 || wing >2
    if(anode <=0 || anode > fNofMaps/2) {
	Warning("GetAnode","Wrong anode number: %d",anode);
	return NULL;
    } // end if ampde <=0 || andoe > fNofMaps/2

    Int_t index = (wing-1)*fNofMaps/2 + anode-1;
    return (TH1F*)(fHis->At(index));
}
//______________________________________________________________________
void AliITSsimulationSDD::WriteToFile(TFile *hfile) {
    // Writes the histograms to a file

    if (!fHis) return;

    hfile->cd();
    Int_t i;
    for(i=0; i<fNofMaps; i++)  fHis->At(i)->Write(); //fAdcs[i]->Write();
    return;
}
//______________________________________________________________________
Float_t AliITSsimulationSDD::GetNoise() {  
    // Returns the noise value
    //Bool_t do10to8=fResponse->Do10to8();
    //noise will always be in the liniar part of the signal
    Int_t decr;
    Int_t threshold = fT1[0];
    char opt1[20], opt2[20];

    fResponse->ParamOptions(opt1,opt2);
    fParam=opt2;
    char *same = strstr(opt1,"same");
    Float_t noise,baseline;
    if (same) {
	fResponse->GetNoiseParam(noise,baseline);
    } else {
	static Bool_t readfile=kTRUE;
	//read baseline and noise from file
	if (readfile) ReadBaseline();
	readfile=kFALSE;
    } // end if same

    TCanvas *c2 = (TCanvas*)gROOT->GetListOfCanvases()->FindObject("c2");
    if(c2) delete c2->GetPrimitive("noisehist");
    if(c2) delete c2->GetPrimitive("anode");
    else     c2=new TCanvas("c2");
    c2->cd();
    c2->SetFillColor(0);

    TH1F *noisehist = new TH1F("noisehist","noise",100,0.,(float)2*threshold);
    TH1F *anode = new TH1F("anode","Anode Projection",fMaxNofSamples,0.,
			   (float)fMaxNofSamples);
    Int_t i,k;
    for (i=0;i<fNofMaps;i++) {
	CompressionParam(i,decr,threshold); 
	if  (!same) GetAnodeBaseline(i,baseline,noise);
	anode->Reset();
	for (k=0;k<fMaxNofSamples;k++) {
	    Float_t signal=(Float_t)fHitMap2->GetSignal(i,k);
	    //if (signal <= (float)threshold) noisehist->Fill(signal-baseline);
	    if (signal <= (float)threshold) noisehist->Fill(signal);
	    anode->Fill((float)k,signal);
	} // end for k
	anode->Draw();
	c2->Update();
    } // end for i
    TF1 *gnoise = new TF1("gnoise","gaus",0.,threshold);
    noisehist->Fit("gnoise","RQ");
    noisehist->Draw();
    c2->Update();
    Float_t mnoise = gnoise->GetParameter(1);
    cout << "mnoise : " << mnoise << endl;
    Float_t rnoise = gnoise->GetParameter(2);
    cout << "rnoise : " << rnoise << endl;
    delete noisehist;
    return rnoise;
}//______________________________________________________________________
void AliITSsimulationSDD::WriteSDigits(AliITSpList *pList){
    // Fills the Summable digits Tree
    Int_t i,ni,j,nj;
    static AliITS *aliITS = (AliITS*)gAlice->GetModule("ITS");

    pList->GetMaxMapIndex(ni,nj);
    for(i=0;i<ni;i++)for(j=0;j<nj;j++){
	if(pList->GetSignalOnly(i,j)>0.5*fT1[0]){ // above small threshold.
	    aliITS->AddSumDigit(*(pList->GetpListItem(i,j)));
//	    cout << "pListSDD: " << *(pList->GetpListItem(i,j)) << endl;
	} // end if
    } // end for i,j
    return;
}
//______________________________________________________________________
void AliITSsimulationSDD::Print() {
    // Print SDD simulation Parameters

    cout << "**************************************************" << endl;
    cout << "   Silicon Drift Detector Simulation Parameters   " << endl;
    cout << "**************************************************" << endl;
    cout << "Flag for Perpendicular tracks: " << (Int_t) fFlag << endl;
    cout << "Flag for noise checking: " << (Int_t) fCheckNoise << endl;
    cout << "Flag to switch off electronics: " << (Int_t) fDoFFT << endl;
    cout << "Number pf Anodes used: " << fNofMaps << endl;
    cout << "Number of Time Samples: " << fMaxNofSamples << endl;
    cout << "Scale size factor: " << fScaleSize << endl;
    cout << "**************************************************" << endl;
}