ITS/AliCascadeComparison.C

   1 /****************************************************************************
   2  *           Very important, delicate and rather obscure macro.             *
   3  *                                                                          *
   4  *               Creates list of "findable" cascades,                       *
   5  *             calculates efficiency, resolutions etc.                      *
   6  *                                                                          *
   7  *  Origin: Christian Kuhn, IReS, Strasbourg, christian.kuhn@ires.in2p3.fr  *
   8  ****************************************************************************/
   9
  10 #ifndef __CINT__
  11   #include <iostream.h>
  12   #include <fstream.h>
  13
  14   #include "TH1.h"
  15   #include "TFile.h"
  16   #include "TTree.h"
  17   #include "TObjArray.h"
  18   #include "TStyle.h"
  19   #include "TCanvas.h"
  20   #include "TLine.h"
  21   #include "TText.h"
  22   #include "TParticle.h"
  23   #include "TStopwatch.h"
  24
  25   #include "AliRun.h"
  26   #include "AliPDG.h"
  27   #include "AliCascadeVertex.h"
  28 #endif
  29
  30 struct GoodCascade {
  31   Int_t nlab,plab;   // V0's daughter labels
  32   Int_t blab;        // Bachelor label
  33   Int_t code;
  34   Float_t px,py,pz;
  35   Float_t x,y,z;
  36 };
  37 Int_t good_cascades(GoodCascade *gt, Int_t max);
  38
  39 Int_t AliCascadeComparison(Int_t code=3312) {
  40   //code= 3312; //kXiMinus
  41   //code=-3312; //kXiPlusBar
  42   //code= 3334; //kOmegaMinus
  43   //code=-3334; //kOmegaPlusBar
  44
  45    cerr<<"Doing comparison...\n";
  46
  47    const Double_t cascadeWindow=0.05, cascadeWidth=0.015;
  48    Double_t cascadeMass=0.5;
  49    switch (code) {
  50    case kXiMinus:
  51    case kXiPlusBar:    cascadeMass=1.32131; break;
  52    case kOmegaMinus:
  53    case kOmegaPlusBar: cascadeMass=1.67245; break;
  54    default: cerr<<"Invalid PDG code !\n"; return 1;
  55    }
  56
  57    TStopwatch timer;
  58
  59    /*** Load reconstructed cascades ***/
  60    TFile *cf=TFile::Open("AliCascadeVertices.root");
  61    if (!cf->IsOpen()){cerr<<"Can't open AliCascadeVertices.root !\n";return 2;}
  62    TObjArray carray(1000);
  63    TTree *cTree=(TTree*)cf->Get("TreeCasc");
  64    TBranch *branch=cTree->GetBranch("cascades");
  65    Int_t nentr=(Int_t)cTree->GetEntries();
  66    for (Int_t i=0; i<nentr; i++) {
  67        AliCascadeVertex *iovertex=new AliCascadeVertex;
  68        branch->SetAddress(&iovertex);
  69        cTree->GetEvent(i);
  70        carray.AddLast(iovertex);
  71    }
  72    cf->Close();
  73
  74    /*** Check if the file with the "good" cascades exists ***/
  75    GoodCascade gc[100];
  76    Int_t ngood=0;
  77    ifstream in("good_cascades");
  78    if (in) {
  79       cerr<<"Reading good cascades...\n";
  80       while (in>>gc[ngood].nlab>>gc[ngood].plab>>
  81                  gc[ngood].blab>>gc[ngood].code>>
  82                  gc[ngood].px>>gc[ngood].py>>gc[ngood].pz>>
  83                  gc[ngood].x >>gc[ngood].y >>gc[ngood].z) {
  84          ngood++;
  85          cerr<<ngood<<'\r';
  86          if (ngood==100) {
  87             cerr<<"Too many good cascades !\n";
  88             break;
  89          }
  90       }
  91       if (!in.eof()) cerr<<"Read error (good_cascades) !\n";
  92    } else {
  93      /*** generate a file with the "good" cascades ***/
  94       cerr<<"Marking good cascades (this will take a while)...\n";
  95       ngood=good_cascades(gc,100);
  96       ofstream out("good_cascades");
  97       if (out) {
  98          for (Int_t ngd=0; ngd<ngood; ngd++)
  99             out<<gc[ngd].nlab<<' '<<gc[ngd].plab<<' '<<
 100                  gc[ngd].blab<<' '<<gc[ngd].code<<' '<<
 101                  gc[ngd].px<<' '<<gc[ngd].py<<' '<<gc[ngd].pz<<' '<<
 102                  gc[ngd].x <<' '<<gc[ngd].y <<' '<<gc[ngd].z <<endl;
 103       } else cerr<<"Can not open file (good_cascades) !\n";
 104       out.close();
 105    }
 106
 107    /*** create some histograms ***/
 108    TH1F *hp=new TH1F("hp","Angular Resolution",30,-30.,30.); //phi resolution
 109    hp->SetXTitle("(mrad)"); hp->SetFillColor(2);
 110    TH1F *hl=new TH1F("hl","Lambda Resolution",30,-30,30);
 111    hl->SetXTitle("(mrad)"); hl->SetFillColor(1); hl->SetFillStyle(3013);
 112    TH1F *hpt=new TH1F("hpt","Relative Pt Resolution",30,-10.,10.);
 113    hpt->SetXTitle("(%)"); hpt->SetFillColor(2);
 114
 115    TH1F *hx=new TH1F("hx","Position Resolution (X,Y)",30,-3.,3.); //x res.
 116    hx->SetXTitle("(mm)"); hx->SetFillColor(6);
 117    TH1F *hy=new TH1F("hy","Position Resolution (Y)",30,-3.,3.);   //y res
 118    hy->SetXTitle("(mm)"); hy->SetFillColor(1); hy->SetFillStyle(3013);
 119    TH1F *hz=new TH1F("hz","Position Resolution (Z)",30,-3.,3.);   //z res.
 120    hz->SetXTitle("(mm)"); hz->SetFillColor(6);
 121
 122    Double_t pmin=0.2, pmax=4.2; Int_t nchan=20;
 123    TH1F *hgood=new TH1F("hgood","Good Cascades",nchan,pmin,pmax);
 124    TH1F *hfound=new TH1F("hfound","Found Cascades",nchan,pmin,pmax);
 125    TH1F *hfake=new TH1F("hfake","Fake Cascades",nchan,pmin,pmax);
 126    TH1F *hg=new TH1F("hg","Efficiency for Good Cascades",nchan,pmin,pmax);
 127    hg->SetLineColor(4); hg->SetLineWidth(2);
 128    TH1F *hf=new TH1F("hf","Probability of Fake Cascades",nchan,pmin,pmax);
 129    hf->SetFillColor(1); hf->SetFillStyle(3013); hf->SetLineWidth(2);
 130
 131    Double_t mmin=cascadeMass-cascadeWindow, mmax=cascadeMass+cascadeWindow;
 132    TH1F *cs =new TH1F("v0s","Cascade Effective Mass",40, mmin, mmax);
 133    cs->SetXTitle("(GeV)"); cs->SetFillColor(6);
 134
 135    Double_t pxg=0.,pyg=0.,ptg=0.;
 136    Int_t nlab=-1, plab=-1, blab=-1;
 137    Int_t i;
 138    for (i=0; i<nentr; i++) {
 139        AliCascadeVertex *cascade=(AliCascadeVertex*)carray.UncheckedAt(i);
 140        cascade->GetV0labels(nlab,plab);
 141        nlab=TMath::Abs(nlab); plab=TMath::Abs(plab);
 142        blab=TMath::Abs(cascade->GetBachelorLabel());
 143
 144        cascade->ChangeMassHypothesis(code);
 145
 146        Double_t mass=cascade->GetEffMass();
 147        cs->Fill(mass);
 148
 149        if (TMath::Abs(mass-cascadeMass)>cascadeWidth) continue;
 150
 151        Int_t j;
 152        for (j=0; j<ngood; j++) {
 153           if (gc[j].code != cascade->GetPdgCode()) continue;
 154           if (gc[j].nlab == nlab)
 155           if (gc[j].plab == plab)
 156           if (gc[j].blab == blab) break;
 157        }
 158
 159        Double_t px,py,pz; cascade->GetPxPyPz(px,py,pz);
 160        Double_t pt=TMath::Sqrt(px*px+py*py);
 161
 162        if (j==ngood) {
 163           hfake->Fill(pt);
 164           cerr<<"Fake cascade: ("<<nlab<<","<<plab<<","<<blab<<")\n";
 165           continue;
 166        }
 167
 168        pxg=gc[j].px; pyg=gc[j].py; ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
 169        Double_t phig=TMath::ATan2(pyg,pxg), phi=TMath::ATan2(py,px);
 170        Double_t lamg=TMath::ATan2(gc[j].pz,ptg), lam=TMath::ATan2(pz,pt);
 171        hp->Fill((phi - phig)*1000.);
 172        hl->Fill((lam - lamg)*1000.);
 173        hpt->Fill((1/pt - 1/ptg)/(1/ptg)*100.);
 174
 175        Double_t x,y,z; cascade->GetXYZ(x,y,z);
 176        hx->Fill((x-gc[j].x)*10);
 177        hy->Fill((y-gc[j].y)*10);
 178        hz->Fill((z-gc[j].z)*10);
 179
 180        hfound->Fill(ptg);
 181        gc[j].nlab=-1;
 182
 183    }
 184    for (i=0; i<ngood; i++) {
 185       if (gc[i].code != code) continue;
 186       pxg=gc[i].px; pyg=gc[i].py; ptg=TMath::Sqrt(pxg*pxg+pyg*pyg);
 187       hgood->Fill(ptg);
 188       nlab=gc[i].nlab; plab=gc[i].plab; blab=gc[i].blab;
 189       if (nlab < 0) continue;
 190      cerr<<"Cascade ("<<nlab<<','<<plab<<","<<blab<<") has not been found !\n";
 191    }
 192
 193    carray.Delete();
 194
 195    Stat_t ng=hgood->GetEntries();
 196    Stat_t nf=hfound->GetEntries();
 197
 198    cerr<<"Number of found cascades: "<<nentr<<" ("<<nf<<" in the peak)\n";
 199    cerr<<"Number of good cascades: "<<ng<<endl;
 200
 201    if (ng!=0)
 202       cerr<<"Integral efficiency is about "<<nf/ng*100.<<" %\n";
 203
 204    gStyle->SetOptStat(111110);
 205    gStyle->SetOptFit(1);
 206
 207    TCanvas *c1=new TCanvas("c1","",0,0,580,610);
 208    c1->Divide(2,2);
 209
 210    c1->cd(1);
 211    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 212    //hp->Fit("gaus");
 213    hp->Draw();
 214    hl->Draw("same"); c1->cd();
 215
 216    c1->cd(2);
 217    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 218    //hpt->Fit("gaus"); c1->cd();
 219    hpt->Draw(); c1->cd();
 220
 221    c1->cd(3);
 222    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 223    //hx->Fit("gaus");
 224    hx->Draw();
 225    hy->Draw("same"); c1->cd();
 226
 227    c1->cd(4);
 228    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 229    //hz->Fit("gaus");
 230    hz->Draw();
 231
 232
 233    TCanvas *c2=new TCanvas("c2","",600,0,580,610);
 234    c2->Divide(1,2);
 235
 236    c2->cd(1);
 237    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 238    hfound->Sumw2(); hgood->Sumw2(); hfake->Sumw2();
 239    hg->Divide(hfound,hgood,1,1.,"b");
 240    hf->Divide(hfake,hgood,1,1.,"b");
 241    hg->SetMaximum(1.4);
 242    hg->SetYTitle("Cascade reconstruction efficiency");
 243    hg->SetXTitle("Pt (GeV/c)");
 244    hg->Draw();
 245
 246    TLine *line1 = new TLine(pmin,1.0,pmax,1.0); line1->SetLineStyle(4);
 247    line1->Draw("same");
 248    TLine *line2 = new TLine(pmin,0.9,pmax,0.9); line2->SetLineStyle(4);
 249    line2->Draw("same");
 250
 251    hf->SetFillColor(1);
 252    hf->SetFillStyle(3013);
 253    hf->SetLineColor(2);
 254    hf->SetLineWidth(2);
 255    hf->Draw("histsame");
 256    TText *text = new TText(0.461176,0.248448,"Fake cascades");
 257    text->SetTextSize(0.05);
 258    text->Draw();
 259    text = new TText(0.453919,1.11408,"Good cascades");
 260    text->SetTextSize(0.05);
 261    text->Draw();
 262
 263
 264    c2->cd(2);
 265    gPad->SetFillColor(42); gPad->SetFrameFillColor(10);
 266    cs->SetXTitle("(GeV/c)");
 267    cs->Fit("gaus","","",cascadeMass-cascadeWidth,cascadeMass+cascadeWidth);
 268    Double_t max=cs->GetMaximum();
 269    TLine *line3 =
 270       new TLine(cascadeMass-cascadeWidth,0.,cascadeMass-cascadeWidth,max);
 271    line3->Draw("same");
 272    TLine *line4 =
 273       new TLine(cascadeMass+cascadeWidth,0.,cascadeMass+cascadeWidth,max);
 274    line4->Draw("same");
 275
 276    timer.Stop(); timer.Print();
 277
 278    return 0;
 279 }
 280
 281
 282
 283 Int_t good_cascades(GoodCascade *gc, Int_t max) {
 284    Int_t nc=0;
 285    /*** Get information about the cuts ***/
 286    Double_t r2min=0.9*0.9;
 287    Double_t r2max=2.9*2.9;
 288
 289    /*** Get labels of the "good" tracks ***/
 290    Double_t dd; Int_t id, label[15000], ngt=0;
 291    ifstream in("good_tracks_its");
 292    if (!in) {
 293      cerr<<"Can't open the file good_tracks_its \n";
 294      return nc;
 295    }
 296    while (in>>label[ngt]>>id>>dd>>dd>>dd>>dd>>dd>>dd) {
 297      ngt++;
 298      if (ngt>=15000) {
 299        cerr<<"Too many good ITS tracks !\n";
 300        return nc;
 301      }
 302    }
 303    if (!in.eof()) {
 304       cerr<<"Read error (good_tracks_its) !\n";
 305       return nc;
 306    }
 307
 308    /*** Get an access to the kinematics ***/
 309    if (gAlice) {delete gAlice; gAlice=0;}
 310
 311    TFile *file=TFile::Open("galice.root");
 312    if (!file->IsOpen()) {cerr<<"Can't open galice.root !\n"; exit(4);}
 313    if (!(gAlice=(AliRun*)file->Get("gAlice"))) {
 314      cerr<<"gAlice has not been found on galice.root !\n";
 315      exit(5);
 316    }
 317
 318    Int_t np=gAlice->GetEvent(0);
 319    while (np--) {
 320       cerr<<np<<'\r';
 321       TParticle *cp=gAlice->Particle(np);
 322
 323       /*** only these cascades are "good" ***/
 324       Int_t code=cp->GetPdgCode();
 325       if (code!=kXiMinus)    if (code!=kXiPlusBar)
 326       if (code!=kOmegaMinus) if (code!=kOmegaPlusBar) continue;
 327
 328       /*** daughter tracks must be "good" ***/
 329       Int_t v0lab=cp->GetFirstDaughter(), blab=cp->GetLastDaughter();
 330       if (v0lab==blab) continue;
 331       if (v0lab<0) continue;
 332       if (blab<0) continue;
 333
 334       TParticle *p0=gAlice->Particle(v0lab);
 335       TParticle *bp=gAlice->Particle(blab);
 336       if ((p0->GetPdgCode()!=kLambda0) && (p0->GetPdgCode()!=kLambda0Bar)) {
 337          TParticle *p=p0; p0=bp; bp=p;
 338          Int_t i=v0lab; v0lab=blab; blab=i;
 339          if ((p0->GetPdgCode()!=kLambda0) && (p0->GetPdgCode()!=kLambda0Bar))
 340                                                                    continue;
 341       }
 342
 343       /** is the bachelor "good" ? **/
 344       Int_t i;
 345       for (i=0; i<ngt; i++) if (label[i]==blab) break;
 346       if (i==ngt) continue;
 347
 348       /** is the V0 "good" ? **/
 349       Int_t plab=p0->GetFirstDaughter(), nlab=p0->GetLastDaughter();
 350       if (nlab==plab) continue;
 351       if (nlab<0) continue;
 352       if (plab<0) continue;
 353
 354       for (i=0; i<ngt; i++) if (label[i]==nlab) break;
 355       if (i==ngt) continue;
 356       for (i=0; i<ngt; i++) if (label[i]==plab) break;
 357       if (i==ngt) continue;
 358
 359       /*** fiducial volume ***/
 360       Double_t x=bp->Vx(), y=bp->Vy(), z=bp->Vz(), r2=x*x+y*y; //bachelor
 361       if (r2<r2min) continue;
 362       if (r2>r2max) continue;
 363       TParticle *pp=gAlice->Particle(plab);
 364       x=pp->Vx(); y=pp->Vy(); r2=x*x+y*y;                      //V0
 365       if (r2<r2min) continue;
 366       if (r2>r2max) continue;
 367
 368       if (gAlice->Particle(plab)->GetPDG()->Charge() < 0.) {
 369          i=plab; plab=nlab; nlab=i;
 370       }
 371
 372       gc[nc].code=code;
 373       gc[nc].plab=plab;   gc[nc].nlab=nlab; gc[nc].blab=blab;
 374       gc[nc].px=cp->Px(); gc[nc].py=cp->Py(); gc[nc].pz=cp->Pz();
 375       gc[nc].x=x; gc[nc].y=y; gc[nc].z=z;
 376       nc++;
 377
 378    }
 379
 380
 381    return nc;
 382 }