Logo ROOT   6.10/09
Reference Guide
testSmooth.C File Reference

Detailed Description

View in nbviewer Open in SWAN Histogram smoothing.

pict1_testSmooth.C.png
int ipad = 1;
TCanvas * c1 = 0;
void smooth_hist(const char * fname, double xmin, double xmax, int n1, int n2) {
std::cout << "smoothing a " << fname << " histogram" << std::endl;
TH1D * h1 = new TH1D("h1","h1",100,xmin,xmax);
TH1D * h2 = new TH1D("h2","h2",100,xmin,xmax);
h1->FillRandom(fname,n1);
TH1D * h1_s = new TH1D(*h1);
h1_s->SetName("h1_s");
h1_s->Smooth();
h2->FillRandom(fname,n2);
double p1 = h1->Chi2Test(h2,"");
double p2 = h1_s->Chi2Test(h2,"UU");
if (p2 < p1) Error("testSmooth","TH1::Smooth is not working correctly - a worst chi2 is obtained");
std::cout << " chi2 test non-smoothed histo " << p1 << std::endl;
std::cout << " chi2 test smoothed histo " << p2 << std::endl;
double a1 = h1->AndersonDarlingTest(h2);
double a2 = h1_s->AndersonDarlingTest(h2);
std::cout << " AD test non-smoothed histo " << a1 << std::endl;
std::cout << " AD test smoothed histo " << a2 << std::endl;
double k1 = h1->KolmogorovTest(h2);
double k2 = h1_s->KolmogorovTest(h2);
std::cout << " KS test non-smoothed histo " << k1 << std::endl;
std::cout << " KS test smoothed histo " << k2 << std::endl;
c1->cd(ipad++);
h1->Draw("E");
h1_s->SetLineColor(kRed);
h1_s->Draw("same");
h2->Scale(double(n1)/n2);
h2->Draw("same");
}
void testSmooth(int n1 = 1000, int n2 = 1000000) {
c1 = new TCanvas();
c1->Divide(1,3);
smooth_hist("gaus",-5,5,n1,n2);
smooth_hist("landau",-5,15,n1,n2);
smooth_hist("expo",-5,0,n1,n2);
}
Author
Rene Brun

Definition in file testSmooth.C.