Hstack

Example of stacked histograms: class THStack.

Author: Rene Brun
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Thursday, April 09, 2020 at 02:18 AM.

In [1]:
THStack *hs = new THStack("hs","Stacked 1D histograms");

Create three 1-d histograms

In [2]:
TH1F *h1st = new TH1F("h1st","test hstack",100,-4,4);
h1st->FillRandom("gaus",20000);
h1st->SetFillColor(kRed);
h1st->SetMarkerStyle(21);
h1st->SetMarkerColor(kRed);
hs->Add(h1st);
TH1F *h2st = new TH1F("h2st","test hstack",100,-4,4);
h2st->FillRandom("gaus",15000);
h2st->SetFillColor(kBlue);
h2st->SetMarkerStyle(21);
h2st->SetMarkerColor(kBlue);
hs->Add(h2st);
TH1F *h3st = new TH1F("h3st","test hstack",100,-4,4);
h3st->FillRandom("gaus",10000);
h3st->SetFillColor(kGreen);
h3st->SetMarkerStyle(21);
h3st->SetMarkerColor(kGreen);
hs->Add(h3st);

TCanvas *cst = new TCanvas("cst","stacked hists",10,10,700,700);
cst->Divide(2,2);

In top left pad, draw the stack with defaults

In [3]:
cst->cd(1);
hs->Draw();

In top right pad, draw the stack in non-stack mode and errors option

In [4]:
cst->cd(2);
gPad->SetGrid();
hs->Draw("nostack,e1p");

In bottom left, draw in stack mode with "lego1" option

In [5]:
cst->cd(3);
gPad->SetFrameFillColor(17);
gPad->SetTheta(3.77);
gPad->SetPhi(2.9);
hs->Draw("lego1");

cst->cd(4);

Create two 2-d histograms and draw them in stack mode

In [6]:
gPad->SetFrameFillColor(17);
THStack *a = new THStack("a","Stacked 2D histograms");
TF2 *f1 = new TF2("f1",
   "xygaus + xygaus(5) + xylandau(10)",-4,4,-4,4);
Double_t params1[] = {130,-1.4,1.8,1.5,1, 150,2,0.5,-2,0.5,
   3600,-2,0.7,-3,0.3};
f1->SetParameters(params1);
TH2F *h2sta = new TH2F("h2sta","h2sta",20,-4,4,20,-4,4);
h2sta->SetFillColor(38);
h2sta->FillRandom("f1",4000);
TF2 *f2 = new TF2("f2","xygaus + xygaus(5)",-4,4,-4,4);
Double_t params2[] = {100,-1.4,1.9,1.1,2, 80,2,0.7,-2,0.5};
f2->SetParameters(params2);
TH2F *h2stb = new TH2F("h2stb","h2stb",20,-4,4,20,-4,4);
h2stb->SetFillColor(46);
h2stb->FillRandom("f2",3000);
a->Add(h2sta);
a->Add(h2stb);
a->Draw();
return cst;

Draw all canvases

In [7]:
gROOT->GetListOfCanvases()->Draw()