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rf313_paramranges.C File Reference

## Detailed Description

Multidimensional models: working with parametrized ranges to define non-rectangular regions for fitting and integration

#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooPolynomial.h"
#include "RooProdPdf.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
using namespace RooFit;
{
// C r e a t e 3 D p d f
// -------------------------
// Define observable (x,y,z)
RooRealVar x("x", "x", 0, 10);
RooRealVar y("y", "y", 0, 10);
RooRealVar z("z", "z", 0, 10);
// Define 3 dimensional pdf
RooRealVar z0("z0", "z0", -0.1, 1);
RooPolynomial px("px", "px", x, RooConst(0.0));
RooPolynomial py("py", "py", y, RooConst(0.0));
RooPolynomial pz("pz", "pz", z, z0);
RooProdPdf pxyz("pxyz", "pxyz", RooArgSet(px, py, pz));
// D e f i n e d n o n - r e c t a n g u l a r r e g i o n R i n ( x , y , z )
// -------------------------------------------------------------------------------------
//
// R = Z[0 - 0.1*Y^2] * Y[0.1*X - 0.9*X] * X[0 - 10]
//
// Construct range parametrized in "R" in y [ 0.1*x, 0.9*x ]
RooFormulaVar ylo("ylo", "0.1*x", x);
RooFormulaVar yhi("yhi", "0.9*x", x);
y.setRange("R", ylo, yhi);
// Construct parametrized ranged "R" in z [ 0, 0.1*y^2 ]
RooFormulaVar zlo("zlo", "0.0*y", y);
RooFormulaVar zhi("zhi", "0.1*y*y", y);
z.setRange("R", zlo, zhi);
// C a l c u l a t e i n t e g r a l o f n o r m a l i z e d p d f i n R
// ----------------------------------------------------------------------------------
// Create integral over normalized pdf model over x,y,z in "R" region
std::unique_ptr<RooAbsReal> intPdf{pxyz.createIntegral(RooArgSet(x, y, z), RooArgSet(x, y, z), "R")};
// Plot value of integral as function of pdf parameter z0
RooPlot *frame = z0.frame(Title("Integral of pxyz over x,y,z in region R"));
intPdf->plotOn(frame);
new TCanvas("rf313_paramranges", "rf313_paramranges", 600, 600);
frame->GetYaxis()->SetTitleOffset(1.6);
frame->Draw();
return;
}
RooArgSet is a container object that can hold multiple RooAbsArg objects.
Definition RooArgSet.h:55
A RooFormulaVar is a generic implementation of a real-valued object, which takes a RooArgList of serv...
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.
Efficient implementation of a product of PDFs of the form.
Definition RooProdPdf.h:33
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
Double_t y[n]
Definition legend1.C:17
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
[#1] INFO:NumericIntegration -- RooRealIntegral::init(pxyz_Int[z|R]_Norm[x,y,z]_Int[y|R]_Int[x|R]) using numeric integrator RooIntegrator1D to calculate Int(x)
[#1] INFO:NumericIntegration -- RooRealIntegral::init(pxyz_Int[z|R]_Norm[x,y,z]_Int[y|R]) using numeric integrator RooIntegrator1D to calculate Int(y)
Date
July 2008

Definition in file rf313_paramranges.C.