Logo ROOT  
Reference Guide
rf706_histpdf.C File Reference

Detailed Description

View in nbviewer Open in SWAN
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
RooDataSet *data1 = p.generate(x, 500);
// Create a binned dataset with 20 bins and 500 events
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
RooDataSet *data2 = p.generate(x, 100000);
// Create a binned dataset with 10 bins and 100K events
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
Definition: TVirtualPad.h:302
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
Definition: RooAbsData.cxx:609
RooArgList is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgList.h:22
The RooDataHist is a container class to hold N-dimensional binned data.
Definition: RooDataHist.h:39
RooDataSet is a container class to hold unbinned data.
Definition: RooDataSet.h:57
RooDataHist * binnedClone(const char *newName=nullptr, const char *newTitle=nullptr) const
Return binned clone of this dataset.
Definition: RooDataSet.cxx:882
RooHistPdf implements a probablity density function sampled from a multidimensional histogram.
Definition: RooHistPdf.h:30
A RooPlot is a plot frame and a container for graphics objects within that frame.
Definition: RooPlot.h:43
TAxis * GetYaxis() const
Definition: RooPlot.cxx:1279
void Draw(Option_t *options=nullptr) override
Draw this plot and all of the elements it contains.
Definition: RooPlot.cxx:652
RooPolynomial implements a polynomial p.d.f of the form.
Definition: RooPolynomial.h:28
RooRealVar represents a variable that can be changed from the outside.
Definition: RooRealVar.h:40
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: Common.h:18
const char * Title
Definition: TXMLSetup.cxx:68
July 2008
Wouter Verkerke

Definition in file rf706_histpdf.C.