rf504_simwstool.C

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/// \file
/// \ingroup tutorial_roofit
/// \notebook -nodraw
///  'ORGANIZATION AND SIMULTANEOUS FITS' RooFit tutorial macro #504
///
///  Using RooSimWSTool to construct a simultaneous p.d.f that is built
///  of variations of an input p.d.f
///
/// \macro_output
/// \macro_code
/// \author 07/2008 - Wouter Verkerke 


#include "RooRealVar.h"
#include "RooCategory.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooConstVar.h"
#include "RooPolynomial.h"
#include "RooSimultaneous.h"
#include "RooAddPdf.h"
#include "RooWorkspace.h"
#include "RooSimWSTool.h"
#include "RooPlot.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "TFile.h"
#include "TH1.h"
using namespace RooFit ;


void rf504_simwstool()
{
   // C r e a t e   m a s t e r   p d f 
   // ---------------------------------
   
   // Construct gauss(x,m,s)
   RooRealVar x("x","x",-10,10) ;
   RooRealVar m("m","m",0,-10,10) ;
   RooRealVar s("s","s",1,-10,10) ;
   RooGaussian gauss("g","g",x,m,s) ;

   // Construct poly(x,p0)
   RooRealVar p0("p0","p0",0.01,0.,1.) ;
   RooPolynomial poly("p","p",x,p0) ;      

   // Construct model = f*gauss(x) + (1-f)*poly(x)
   RooRealVar f("f","f",0.5,0.,1.) ;
   RooAddPdf model("model","model",RooArgSet(gauss,poly),f) ;



   // C r e a t e   c a t e g o r y   o b s e r v a b l e s   f o r   s p l i t t i n g
   // ----------------------------------------------------------------------------------

   // Define two categories that can be used for splitting
   RooCategory c("c","c") ;
   c.defineType("run1") ;
   c.defineType("run2") ;

   RooCategory d("d","d") ;
   d.defineType("foo") ;
   d.defineType("bar") ;



   // S e t u p   S i m W S T o o l 
   // -----------------------------

   // Import ingredients in a workspace
   RooWorkspace w("w","w") ;
   w.import(RooArgSet(model,c,d)) ;

   // Make Sim builder tool
   RooSimWSTool sct(w) ;


   // B u i l d   a   s i m u l t a n e o u s   m o d e l   w i t h   o n e   s p l i t
   // ---------------------------------------------------------------------------------

   // Construct a simultaneous p.d.f with the following form
   //
   // model_run1(x) = f*gauss_run1(x,m_run1,s) + (1-f)*poly
   // model_run2(x) = f*gauss_run2(x,m_run2,s) + (1-f)*poly
   // simpdf(x,c) = model_run1(x) if c=="run1"
   //             = model_run2(x) if c=="run2"
   //
   // Returned p.d.f is owned by the workspace
   RooSimultaneous* model_sim = sct.build("model_sim","model",SplitParam("m","c")) ;

   // Print tree structure of model
   model_sim->Print("t") ;

   // Adjust model_sim parameters in workspace
   w.var("m_run1")->setVal(-3) ;
   w.var("m_run2")->setVal(+3) ;

   // Print contents of workspace
   w.Print("v") ;



   // B u i l d   a   s i m u l t a n e o u s   m o d e l   w i t h   p r o d u c t   s p l i t
   // -----------------------------------------------------------------------------------------

   // Build another simultaneous p.d.f using a composite split in states c X d
   RooSimultaneous* model_sim2 = sct.build("model_sim2","model",SplitParam("p0","c,d")) ;

   // Print tree structure of this model
   model_sim2->Print("t") ;

}