Illustrate use of the TH1::GetCumulative method.
Author: M. Schiller
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Wednesday, April 17, 2024 at 11:12 AM.
TH1* h = new TH1D("h", "h", 100, -5., 5.);
gRandom->SetSeed();
h->FillRandom("gaus", 1u << 16);
get the cumulative of h
TH1* hc = h->GetCumulative();
check that c has the "right" contents
Double_t* integral = h->GetIntegral();
for (Int_t i = 1; i <= hc->GetNbinsX(); ++i) {
assert(std::abs(integral[i] * h->GetEntries() - hc->GetBinContent(i)) < 1e-7);
}
draw histogram together with its cumulative distribution
TCanvas* c = new TCanvas;
c->Divide(1,2);
c->cd(1);
h->Draw();
c->cd(2);
hc->Draw();
c->Update();
return c;
Draw all canvases
%jsroot on
gROOT->GetListOfCanvases()->Draw()