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Reference Guide
testSmooth.C File Reference

Detailed Description

View in nbviewer Open in SWAN 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);
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->SetLineColor(kGreen);
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.

TH1::AndersonDarlingTest
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:7569
TH1::Chi2Test
virtual Double_t Chi2Test(const TH1 *h2, Option_t *option="UU", Double_t *res=0) const
test for comparing weighted and unweighted histograms
Definition: TH1.cxx:1949
kGreen
@ kGreen
Definition: Rtypes.h:66
xmax
float xmax
Definition: THbookFile.cxx:95
TH1D
1-D histogram with a double per channel (see TH1 documentation)}
Definition: TH1.h:615
TH1::SetName
virtual void SetName(const char *name)
Change the name of this histogram.
Definition: TH1.cxx:8415
h1
TH1F * h1
Definition: legend1.C:5
TH1::KolmogorovTest
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:7683
xmin
float xmin
Definition: THbookFile.cxx:95
TH1::AddDirectory
static void AddDirectory(Bool_t add=kTRUE)
Sets the flag controlling the automatic add of histograms in memory.
Definition: TH1.cxx:1225
kRed
@ kRed
Definition: Rtypes.h:66
TH1::FillRandom
virtual void FillRandom(const char *fname, Int_t ntimes=5000)
Fill histogram following distribution in function fname.
Definition: TH1.cxx:3444
TH1::Smooth
virtual void Smooth(Int_t ntimes=1, Option_t *option="")
Smooth bin contents of this histogram.
Definition: TH1.cxx:6511
TCanvas
Definition: TCanvas.h:23
TH1::Scale
virtual void Scale(Double_t c1=1, Option_t *option="")
Multiply this histogram by a constant c1.
Definition: TH1.cxx:6245
TH1::Draw
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition: TH1.cxx:2997
Error
void Error(const char *location, const char *msgfmt,...)
Use this function in case an error occurred.
Definition: TError.cxx:187
c1
return c1
Definition: legend1.C:41