rf207_comptools.C File Reference

Detailed Description

Addition and convolution: tools and utilities for manipulation of composite objects

 
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooChebychev.h"
#include "RooExponential.h"
#include "RooAddPdf.h"
#include "RooPlot.h"
#include "RooCustomizer.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "TH1.h"
using namespace RooFit;
 
void rf207_comptools()
{
 
   // S e t u p   c o m p o s i t e    p d f,   d a t a s e t
   // --------------------------------------------------------
 
   // 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 sigma("sigma", "width of gaussians", 0.5);
   RooGaussian sig("sig", "Signal component 1", x, mean, sigma);
 
   // 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 exponential 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);
 
   // Create dummy dataset that has more observables than the above pdf
   RooRealVar y("y", "y", -10, 10);
   RooDataSet data("data", "data", RooArgSet(x, y));
 
   // ---------------------------------------------------
   // B a s i c   i n f o r m a t i o n   r e q u e s t s
   // ===================================================
 
   // G e t   l i s t   o f   o b s e r v a b l e s
   // ---------------------------------------------
 
   // Get list of observables of pdf in context of a dataset
   //
   // Observables are define each context as the variables
   // shared between a model and a dataset. In this case
   // that is the variable 'x'
 
   std::unique_ptr<RooArgSet> model_obs{model.getObservables(data)};
   model_obs->Print("v");
 
   // G e t   l i s t   o f   p a r a m e t e r s
   // -------------------------------------------
 
   // Get list of parameters, given list of observables
   std::unique_ptr<RooArgSet> model_params{model.getParameters(x)};
   model_params->Print("v");
 
   // Get list of parameters, given a dataset
   // (Gives identical results to operation above)
   std::unique_ptr<RooArgSet> model_params2{model.getParameters(data)};
   model_params2->Print();
 
   // G e t   l i s t   o f   c o m p o n e n t s
   // -------------------------------------------
 
   // Get list of component objects, including top-level node
   std::unique_ptr<RooArgSet> model_comps{model.getComponents()};
   model_comps->Print("v");
 
   // -------------------------------------------------------------------------------
   // M o d i f i c a t i o n s   t o   s t r u c t u r e   o f   c o m p o s i t e s
   // ===============================================================================
 
   // Create a second Gaussian
   RooRealVar sigma2("sigma2", "width of gaussians", 1);
   RooGaussian sig2("sig2", "Signal component 1", x, mean, sigma2);
 
   // Create a sum of the original Gaussian plus the new second Gaussian
   RooRealVar sig1frac("sig1frac", "fraction of component 1 in signal", 0.8, 0., 1.);
   RooAddPdf sigsum("sigsum", "sig+sig2", RooArgList(sig, sig2), sig1frac);
 
   // Construct a customizer utility to customize model
   RooCustomizer cust(model, "cust");
 
   // Instruct the customizer to replace node 'sig' with node 'sigsum'
   cust.replaceArg(sig, sigsum);
 
   // Build a clone of the input pdf according to the above customization
   // instructions. Each node that requires modified is clone so that the
   // original pdf remained untouched. The name of each cloned node is that
   // of the original node suffixed by the name of the customizer object
   //
   // The returned head node own all nodes that were cloned as part of
   // the build process so when cust_clone is deleted so will all other
   // nodes that were created in the process.
   RooAbsPdf *cust_clone = (RooAbsPdf *)cust.build(true);
 
   // Print structure of clone of model with sig->sigsum replacement.
   cust_clone->Print("t");
 
   delete cust_clone;
}

 
[#0] WARNING:InputArguments -- The parameter 'sigma' with range [-inf, inf] of the RooGaussian 'sig' exceeds the safe range of (0, inf). Advise to limit its range.
  1) 0x7ffc733ddb50 RooRealVar:: x = 5  L(0 - 10)  "x"
  1) 0x7ffc733d9cf0 RooRealVar::       a0 = 0.5  L(0 - 1)  "a0"
  2) 0x7ffc733da0d8 RooRealVar::       a1 = 0.2  L(0 - 1)  "a1"
  3) 0x7ffc733da4c0 RooRealVar::    alpha = -1 C  L(-INF - +INF)  "alpha"
  4) 0x7ffc733da8a8 RooRealVar:: bkg1frac = 0.2  L(0 - 1)  "fraction of component 1 in background"
  5) 0x7ffc733dac90 RooRealVar::  bkgfrac = 0.5  L(0 - 1)  "fraction of background"
  6) 0x7ffc733dc0d8 RooRealVar::     mean = 5 C  L(-INF - +INF)  "mean of gaussians"
  7) 0x7ffc733d9908 RooRealVar::    sigma = 0.5 C  L(-INF - +INF)  "width of gaussians"
RooArgSet::parameters = (a0,a1,alpha,bkg1frac,bkgfrac,mean,sigma)
  1) 0x7ffc733dced8 RooAddPdf:: model[ bkgfrac * bkg + [%] * sig ] = 0.582695/1  "g1+g2+a"
  2) 0x7ffc733db9b8 RooAddPdf::   bkg[ bkg1frac * bkg1 + [%] * bkg2 ] = 0.16539/1  "Signal"
  3) 0x7ffc733d8ee0 RooChebychev::  bkg1[ x=x coefficients=(a0,a1) ] = 0.8  "Background 1"
  4) 0x7ffc733d9410 RooExponential::  bkg2[ x=x c=alpha ] = 0.00673795  "Background 2"
  5) 0x7ffc733db460 RooGaussian::   sig[ x=x mean=mean sigma=sigma ] = 1  "Signal component 1"
[#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.
[#1] INFO:ObjectHandling -- RooCustomizer::build(model): tree node sig will be replaced by sigsum
[#1] INFO:ObjectHandling -- RooCustomizer::build(model) Branch node RooAddPdf::model cloned: depends on a replaced parameter
[#1] INFO:ObjectHandling -- RooCustomizer::build(model) Branch node sig is already replaced
0x4cca390 RooAddPdf::model_cust = 0.582695/1 [Auto,Clean] 
  0x7ffc733db9b8/V- RooAddPdf::bkg = 0.16539/1 [Auto,Clean] 
    0x7ffc733d8ee0/V- RooChebychev::bkg1 = 0.8 [Auto,Dirty] 
      0x7ffc733ddb50/V- RooRealVar::x = 5
      0x7ffc733d9cf0/V- RooRealVar::a0 = 0.5
      0x7ffc733da0d8/V- RooRealVar::a1 = 0.2
    0x7ffc733da8a8/V- RooRealVar::bkg1frac = 0.2
    0x7ffc733d9410/V- RooExponential::bkg2 = 0.00673795 [Auto,Dirty] 
      0x7ffc733ddb50/V- RooRealVar::x = 5
      0x7ffc733da4c0/V- RooRealVar::alpha = -1
  0x7ffc733dac90/V- RooRealVar::bkgfrac = 0.5
  0x7ffc733ddf38/V- RooAddPdf::sigsum = 1/1 [Auto,Clean] 
    0x7ffc733db460/V- RooGaussian::sig = 1 [Auto,Dirty] 
      0x7ffc733ddb50/V- RooRealVar::x = 5
      0x7ffc733dc0d8/V- RooRealVar::mean = 5
      0x7ffc733d9908/V- RooRealVar::sigma = 0.5
    0x7ffc733dc8a8/V- RooRealVar::sig1frac = 0.8
    0x7ffc733dd5f8/V- RooGaussian::sig2 = 1 [Auto,Dirty] 
      0x7ffc733ddb50/V- RooRealVar::x = 5
      0x7ffc733dc0d8/V- RooRealVar::mean = 5
      0x7ffc733dc4c0/V- RooRealVar::sigma2 = 1

Date

July 2008

Author

Wouter Verkerke

Definition in file rf207_comptools.C.