Addition and convolution: tools for visualization of RooAbsArg expression trees
Author: Wouter Verkerke
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Wednesday, April 17, 2024 at 11:17 AM.
%%cpp -d
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooChebychev.h"
#include "RooAddPdf.h"
#include "RooExponential.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
using namespace RooFit;
Declare observable x
RooRealVar x("x", "x", 0, 10);
Create two Gaussian PDFs g1(x,mean1,sigma) anf g2(x,mean2,sigma) and their parameters
RooRealVar mean("mean", "mean of gaussians", 5);
RooRealVar sigma1("sigma1", "width of gaussians", 0.5);
RooRealVar sigma2("sigma2", "width of gaussians", 1);
RooGaussian sig1("sig1", "Signal component 1", x, mean, sigma1);
RooGaussian sig2("sig2", "Signal component 2", x, mean, sigma2);
[#0] WARNING:InputArguments -- The parameter 'sigma1' with range [-inf, inf] of the RooGaussian 'sig1' exceeds the safe range of (0, inf). Advise to limit its range. [#0] WARNING:InputArguments -- The parameter 'sigma2' with range [-inf, inf] of the RooGaussian 'sig2' exceeds the safe range of (0, inf). Advise to limit its range.
Sum the signal components into a composite signal pdf
RooRealVar sig1frac("sig1frac", "fraction of component 1 in signal", 0.8, 0., 1.);
RooAddPdf sig("sig", "Signal", RooArgList(sig1, sig2), sig1frac);
Build Chebychev polynomial pdf
RooRealVar a0("a0", "a0", 0.5, 0., 1.);
RooRealVar a1("a1", "a1", 0.2, 0., 1.);
RooChebychev bkg1("bkg1", "Background 1", x, RooArgSet(a0, a1));
Build expontential pdf
RooRealVar alpha("alpha", "alpha", -1);
RooExponential bkg2("bkg2", "Background 2", x, alpha);
Sum the background components into a composite background pdf
RooRealVar bkg1frac("bkg1frac", "fraction of component 1 in background", 0.2, 0., 1.);
RooAddPdf bkg("bkg", "Signal", RooArgList(bkg1, bkg2), bkg1frac);
Sum the composite signal and background
RooRealVar bkgfrac("bkgfrac", "fraction of background", 0.5, 0., 1.);
RooAddPdf model("model", "g1+g2+a", RooArgList(bkg, sig), bkgfrac);
Print tree to stdout
model.Print("t");
0x7f11a80163e8 RooAddPdf::model = 0.582695/1 [Auto,Clean] 0x7f11a80193e8/V- RooAddPdf::bkg = 0.16539/1 [Auto,Clean] 0x7f11a801f7d0/V- RooChebychev::bkg1 = 0.8 [Auto,Dirty] 0x7f11a85fc000/V- RooRealVar::x = 5 0x7f11a801f000/V- RooRealVar::a0 = 0.5 0x7f11a801f3e8/V- RooRealVar::a1 = 0.2 0x7f11a8019000/V- RooRealVar::bkg1frac = 0.2 0x7f11a801c3e8/V- RooExponential::bkg2 = 0.00673795 [Auto,Dirty] 0x7f11a85fc000/V- RooRealVar::x = 5 0x7f11a801c000/V- RooRealVar::alpha = -1 0x7f11a8016000/V- RooRealVar::bkgfrac = 0.5 0x7f11a811e3e8/V- RooAddPdf::sig = 1/1 [Auto,Clean] 0x7f11a8121bb8/V- RooGaussian::sig1 = 1 [Auto,Dirty] 0x7f11a85fc000/V- RooRealVar::x = 5 0x7f11a8121000/V- RooRealVar::mean = 5 0x7f11a81213e8/V- RooRealVar::sigma1 = 0.5 0x7f11a811e000/V- RooRealVar::sig1frac = 0.8 0x7f11a8122110/V- RooGaussian::sig2 = 1 [Auto,Dirty] 0x7f11a85fc000/V- RooRealVar::x = 5 0x7f11a8121000/V- RooRealVar::mean = 5 0x7f11a81217d0/V- RooRealVar::sigma2 = 1
Print tree to file
model.printCompactTree("", "rf206_asciitree.txt");
Print GraphViz DOT file with representation of tree
model.graphVizTree("rf206_model.dot");