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hist017_TH1_smooth.C File Reference

Detailed Description

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Histogram smoothing.

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);
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->SetLineColor(kGreen);
h2->Draw("same");
}
void hist017_TH1_smooth(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);
}
@ kRed
Definition Rtypes.h:66
@ kGreen
Definition Rtypes.h:66
ROOT::Detail::TRangeCast< T, true > TRangeDynCast
TRangeDynCast is an adapter class that allows the typed iteration through a TCollection.
void Error(const char *location, const char *msgfmt,...)
Use this function in case an error occurred.
Definition TError.cxx:185
float xmin
float xmax
The Canvas class.
Definition TCanvas.h:23
1-D histogram with a double per channel (see TH1 documentation)
Definition TH1.h:693
virtual void FillRandom(TF1 *f1, Int_t ntimes=5000, TRandom *rng=nullptr)
Definition TH1.cxx:3499
static void AddDirectory(Bool_t add=kTRUE)
Sets the flag controlling the automatic add of histograms in memory.
Definition TH1.cxx:1263
void Draw(Option_t *option="") override
Draw this histogram with options.
Definition TH1.cxx:3037
virtual Double_t AndersonDarlingTest(const TH1 *h2, Option_t *option="") const
Statistical test of compatibility in shape between this histogram and h2, using the Anderson-Darling ...
Definition TH1.cxx:8064
virtual Double_t Chi2Test(const TH1 *h2, Option_t *option="UU", Double_t *res=nullptr) const
test for comparing weighted and unweighted histograms.
Definition TH1.cxx:1979
virtual Double_t KolmogorovTest(const TH1 *h2, Option_t *option="") const
Statistical test of compatibility in shape between this histogram and h2, using Kolmogorov test.
Definition TH1.cxx:8180
return c1
Definition legend1.C:41
TH1F * h1
Definition legend1.C:5
Date
July 2016
Author
Rene Brun

Definition in file hist017_TH1_smooth.C.