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canvas2.C File Reference

Example of canvas partitioning. More...

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Detailed Description

Example of canvas partitioning.

Sometimes the Divide() method is not appropriate to divide a Canvas. Because of the left and right margins, all the pads do not have the same width and height. CanvasPartition does that properly. This example also ensure that the axis labels and titles have the same sizes and that the tick marks length is uniform.

pict1_canvas2.C.png
void CanvasPartition(TCanvas *C,const Int_t Nx = 2,const Int_t Ny = 2,
Float_t lMargin = 0.15, Float_t rMargin = 0.05,
Float_t bMargin = 0.15, Float_t tMargin = 0.05);
void canvas2()
{
TCanvas *C = (TCanvas*) gROOT->FindObject("C");
if (C) delete C;
C = new TCanvas("C","canvas",1024,640);
C->SetFillStyle(4000);
// Number of PADS
const Int_t Nx = 5;
const Int_t Ny = 5;
// Margins
Float_t lMargin = 0.12;
Float_t rMargin = 0.05;
Float_t bMargin = 0.15;
Float_t tMargin = 0.05;
// Canvas setup
CanvasPartition(C,Nx,Ny,lMargin,rMargin,bMargin,tMargin);
// Dummy histogram.
TH1F *h = (TH1F*) gROOT->FindObject("histo");
if (h) delete h;
h = new TH1F("histo","",100,-5.0,5.0);
h->FillRandom("gaus",10000);
h->GetXaxis()->SetTitle("x axis");
h->GetYaxis()->SetTitle("y axis");
TPad *pad[Nx][Ny];
for (Int_t i=0;i<Nx;i++) {
for (Int_t j=0;j<Ny;j++) {
C->cd(0);
// Get the pads previously created.
char pname[16];
sprintf(pname,"pad_%i_%i",i,j);
pad[i][j] = (TPad*) gROOT->FindObject(pname);
pad[i][j]->Draw();
pad[i][j]->SetFillStyle(4000);
pad[i][j]->SetFrameFillStyle(4000);
pad[i][j]->cd();
// Size factors
Float_t xFactor = pad[0][0]->GetAbsWNDC()/pad[i][j]->GetAbsWNDC();
Float_t yFactor = pad[0][0]->GetAbsHNDC()/pad[i][j]->GetAbsHNDC();
char hname[16];
sprintf(hname,"h_%i_%i",i,j);
TH1F *hFrame = (TH1F*) h->Clone(hname);
hFrame->Reset();
hFrame->Draw();
// y axis range
hFrame->GetYaxis()->SetRangeUser(0.0001,1.2*h->GetMaximum());
// Format for y axis
hFrame->GetYaxis()->SetLabelFont(43);
hFrame->GetYaxis()->SetLabelSize(16);
hFrame->GetYaxis()->SetLabelOffset(0.02);
hFrame->GetYaxis()->SetTitleFont(43);
hFrame->GetYaxis()->SetTitleSize(16);
hFrame->GetYaxis()->SetTitleOffset(5);
hFrame->GetYaxis()->CenterTitle();
hFrame->GetYaxis()->SetNdivisions(505);
// TICKS Y Axis
hFrame->GetYaxis()->SetTickLength(xFactor*0.04/yFactor);
// Format for x axis
hFrame->GetXaxis()->SetLabelFont(43);
hFrame->GetXaxis()->SetLabelSize(16);
hFrame->GetXaxis()->SetLabelOffset(0.02);
hFrame->GetXaxis()->SetTitleFont(43);
hFrame->GetXaxis()->SetTitleSize(16);
hFrame->GetXaxis()->SetTitleOffset(5);
hFrame->GetXaxis()->CenterTitle();
hFrame->GetXaxis()->SetNdivisions(505);
// TICKS X Axis
hFrame->GetXaxis()->SetTickLength(yFactor*0.06/xFactor);
h->Draw("same");
}
}
C->cd();
}
void CanvasPartition(TCanvas *C,const Int_t Nx,const Int_t Ny,
Float_t lMargin, Float_t rMargin,
Float_t bMargin, Float_t tMargin)
{
if (!C) return;
// Setup Pad layout:
Float_t vSpacing = 0.0;
Float_t vStep = (1.- bMargin - tMargin - (Ny-1) * vSpacing) / Ny;
Float_t hSpacing = 0.0;
Float_t hStep = (1.- lMargin - rMargin - (Nx-1) * hSpacing) / Nx;
Float_t vposd,vposu,vmard,vmaru,vfactor;
Float_t hposl,hposr,hmarl,hmarr,hfactor;
for (Int_t i=0;i<Nx;i++) {
if (i==0) {
hposl = 0.0;
hposr = lMargin + hStep;
hfactor = hposr-hposl;
hmarl = lMargin / hfactor;
hmarr = 0.0;
} else if (i == Nx-1) {
hposl = hposr + hSpacing;
hposr = hposl + hStep + rMargin;
hfactor = hposr-hposl;
hmarl = 0.0;
hmarr = rMargin / (hposr-hposl);
} else {
hposl = hposr + hSpacing;
hposr = hposl + hStep;
hfactor = hposr-hposl;
hmarl = 0.0;
hmarr = 0.0;
}
for (Int_t j=0;j<Ny;j++) {
if (j==0) {
vposd = 0.0;
vposu = bMargin + vStep;
vfactor = vposu-vposd;
vmard = bMargin / vfactor;
vmaru = 0.0;
} else if (j == Ny-1) {
vposd = vposu + vSpacing;
vposu = vposd + vStep + tMargin;
vfactor = vposu-vposd;
vmard = 0.0;
vmaru = tMargin / (vposu-vposd);
} else {
vposd = vposu + vSpacing;
vposu = vposd + vStep;
vfactor = vposu-vposd;
vmard = 0.0;
vmaru = 0.0;
}
C->cd(0);
char name[16];
sprintf(name,"pad_%i_%i",i,j);
TPad *pad = (TPad*) gROOT->FindObject(name);
if (pad) delete pad;
pad = new TPad(name,"",hposl,vposd,hposr,vposu);
pad->SetLeftMargin(hmarl);
pad->SetRightMargin(hmarr);
pad->SetBottomMargin(vmard);
pad->SetTopMargin(vmaru);
pad->SetBorderMode(0);
pad->SetBorderSize(0);
pad->Draw();
}
}
}
Author
Olivier Couet

Definition in file canvas2.C.