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rf706_histpdf.C File Reference

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Special pdf's: histogram-based pdfs and functions

#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooPolynomial.h"
#include "RooHistPdf.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
using namespace RooFit;
// C r e a t e p d f f o r s a m p l i n g
// ---------------------------------------------
RooRealVar x("x", "x", 0, 20);
RooPolynomial p("p", "p", x, RooArgList(0.01, -0.01, 0.0004));
// C r e a t e l o w s t a t s h i s t o g r a m
// ---------------------------------------------------
// Sample 500 events from p
std::unique_ptr<RooDataSet> data1{p.generate(x, 500)};
// Create a binned dataset with 20 bins and 500 events
std::unique_ptr<RooDataHist> hist1{data1->binnedClone()};
// Represent data in dh as pdf in x
RooHistPdf histpdf1("histpdf1", "histpdf1", x, *hist1, 0);
// Plot unbinned data and histogram pdf overlaid
RooPlot *frame1 = x.frame(Title("Low statistics histogram pdf"), Bins(100));
// C r e a t e h i g h s t a t s h i s t o g r a m
// -----------------------------------------------------
// Sample 100000 events from p
std::unique_ptr<RooDataSet> data2{p.generate(x, 100000)};
// Create a binned dataset with 10 bins and 100K events
std::unique_ptr<RooDataHist> hist2{data2->binnedClone()};
// Represent data in dh as pdf in x, apply 2nd order interpolation
RooHistPdf histpdf2("histpdf2", "histpdf2", x, *hist2, 2);
// Plot unbinned data and histogram pdf overlaid
RooPlot *frame2 = x.frame(Title("High stats histogram pdf with interpolation"), Bins(100));
TCanvas *c = new TCanvas("rf706_histpdf", "rf706_histpdf", 800, 400);
#define c(i)
Definition RSha256.hxx:101
winID h TVirtualViewer3D TVirtualGLPainter p
#define gPad
RooArgList is a container object that can hold multiple RooAbsArg objects.
Definition RooArgList.h:22
A propability density function sampled from a multidimensional histogram.
Definition RooHistPdf.h:30
Plot frame and a container for graphics objects within that frame.
Definition RooPlot.h:43
static RooPlot * frame(const RooAbsRealLValue &var, double xmin, double xmax, Int_t nBins)
Create a new frame for a given variable in x.
Definition RooPlot.cxx:237
TAxis * GetYaxis() const
Definition RooPlot.cxx:1276
void Draw(Option_t *options=nullptr) override
Draw this plot and all of the elements it contains.
Definition RooPlot.cxx:649
RooPolynomial implements a polynomial p.d.f of the form.
Variable that can be changed from the outside.
Definition RooRealVar.h:37
virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title.
Definition TAttAxis.cxx:298
The Canvas class.
Definition TCanvas.h:23
RooCmdArg Bins(Int_t nbin)
Double_t x[n]
Definition legend1.C:17
The namespace RooFit contains mostly switches that change the behaviour of functions of PDFs (or othe...
Definition JSONIO.h:26
const char * Title
Definition TXMLSetup.cxx:68
July 2008
Wouter Verkerke

Definition in file rf706_histpdf.C.