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1/// \file
2/// \ingroup tutorial_roostats
3/// \notebook -js
5/// \macro_image
6/// \macro_output
7/// \macro_code
9/// \author Lorenzo Moneta
11using namespace RooFit;
12void TestNonCentral()
15 RooWorkspace w("w");
16 // k <2, must use sum
17 w.factory("NonCentralChiSquare::nc(x[0,50],k[1.99,0,5],lambda[5])");
18 // kk > 2 can use bessel
19 w.factory("NonCentralChiSquare::ncc(x,kk[2.01,0,5],lambda)");
20 // kk > 2, force sum
21 w.factory("NonCentralChiSquare::nccc(x,kk,lambda)");
22 ((RooNonCentralChiSquare *)w.pdf("nccc"))->SetForceSum(true);
24 // a normal "central" chi-square for comparison when lambda->0
25 w.factory("ChiSquarePdf::cs(x,k)");
27 // w.var("kk")->setVal(4.); // test a large kk
29 RooDataSet *ncdata = w.pdf("nc")->generate(*w.var("x"), 100);
30 RooDataSet *csdata = w.pdf("cs")->generate(*w.var("x"), 100);
31 RooPlot *plot = w.var("x")->frame();
32 ncdata->plotOn(plot, MarkerColor(kRed));
33 csdata->plotOn(plot, MarkerColor(kBlue));
34 w.pdf("nc")->plotOn(plot, LineColor(kRed));
35 w.pdf("ncc")->plotOn(plot, LineColor(kGreen));
36 w.pdf("nccc")->plotOn(plot, LineColor(kYellow), LineStyle(kDashed));
37 w.pdf("cs")->plotOn(plot, LineColor(kBlue), LineStyle(kDotted));
38 plot->Draw();
@ kRed
Definition Rtypes.h:66
@ kGreen
Definition Rtypes.h:66
@ kBlue
Definition Rtypes.h:66
@ kYellow
Definition Rtypes.h:66
@ kDashed
Definition TAttLine.h:48
@ kDotted
Definition TAttLine.h:48
virtual RooPlot * plotOn(RooPlot *frame, const RooCmdArg &arg1=RooCmdArg::none(), const RooCmdArg &arg2=RooCmdArg::none(), const RooCmdArg &arg3=RooCmdArg::none(), const RooCmdArg &arg4=RooCmdArg::none(), const RooCmdArg &arg5=RooCmdArg::none(), const RooCmdArg &arg6=RooCmdArg::none(), const RooCmdArg &arg7=RooCmdArg::none(), const RooCmdArg &arg8=RooCmdArg::none()) const
RooDataSet is a container class to hold unbinned data.
Definition RooDataSet.h:33
The PDF of the Non-Central Chi Square distribution for n degrees of freedom.
A RooPlot is a plot frame and a container for graphics objects within that frame.
Definition RooPlot.h:44
static RooPlot * frame(const RooAbsRealLValue &var, Double_t xmin, Double_t xmax, Int_t nBins)
Create a new frame for a given variable in x.
Definition RooPlot.cxx:249
virtual void Draw(Option_t *options=0)
Draw this plot and all of the elements it contains.
Definition RooPlot.cxx:691
The RooWorkspace is a persistable container for RooFit projects.
RooCmdArg MarkerColor(Color_t color)
RooCmdArg LineColor(Color_t color)
RooCmdArg LineStyle(Style_t style)
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...