rf512_wsfactory_oper.C

Go to the documentation of this file.

/// \file
/// \ingroup tutorial_roofit
/// \notebook -nodraw
/// Organization and simultaneous fits: operator expressions and expression-based basic p.d.f.s in the workspace factory
/// syntax
///
/// \macro_output
/// \macro_code
/// \author 04/2009 - Wouter Verkerke

#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "RooConstVar.h"
#include "RooChebychev.h"
#include "RooAddPdf.h"
#include "RooWorkspace.h"
#include "RooPlot.h"
#include "TCanvas.h"
#include "TAxis.h"
using namespace RooFit;

void rf512_wsfactory_oper()
{
   RooWorkspace *w = new RooWorkspace("w");

   // You can define typedefs for even shorter construction semantics
   w->factory("$Typedef(Gaussian,Gaus)");
   w->factory("$Typedef(Chebychev,Cheby)");

   // O p e r a t o r   p . d . f .   e x a m p l e s
   // ------------------------------------------------

   // PDF addition is done with SUM (coef1*pdf1,pdf2)
   w->factory("SUM::summodel( f[0,1]*Gaussian::gx(x[-10,10],m[0],1.0), Chebychev::ch(x,{0.1,0.2,-0.3}) )");

   // Extended PDF addition is done with SUM (yield1*pdf1,yield2*pdf2)
   w->factory("SUM::extsummodel( Nsig[0,1000]*gx, Nbkg[0,1000]*ch )");

   // PDF multiplication is done with PROD ( pdf1, pdf2 )
   w->factory("PROD::gxz( gx, Gaussian::gz(z[-10,10],0,1) )");

   // Conditional p.d.f multiplication is done with PROD ( pdf1|obs, pdf2 )
   w->factory("Gaussian::gy( y[-10,10], x, 1.0 )");
   w->factory("PROD::gxycond( gy|x, gx )");

   // Convolution (numeric/ fft) is done with NCONV/FCONV (obs,pdf1,pdf2)
   w->factory("FCONV::lxg( x, Gaussian::g(x,mg[0],1), Landau::lc(x,0,1) )");

   // Simultaneous p.d.f.s are constructed with SIMUL( index, state1=pdf1, state2=pdf2,...)
   w->factory("SIMUL::smodel( c[A=0,B=1], A=Gaussian::gs(x,m,s[1]), B=Landau::ls(x,0,1) )");

   // O p e r a t o r   f u n c t i o n   e x a m p l e s
   // ---------------------------------------------------

   // Function multiplication is done with prod (func1, func2,...)
   w->factory("prod::uv(u[10],v[10])");

   // Function addition is done with sum(func1,func2)
   w->factory("sum::uv2(u,v)");

   // I n t e r p r e t e d   a n d   c o m p i l e d   e x p r e s s i o n   b a s e d   p . d . f . s .
   // ---------------------------------------------------------------------------------------------------

   // Create a RooGenericPdf interpreted p.d.f. You can use single quotes to pass the expression string argument
   w->factory("EXPR::G('x*x+1',x)");

   // Create a custom compiled p.d.f similar to the above interpreted p.d.f.
   // The code required to make this p.d.f. is automatically embedded in the workspace
   w->factory("CEXPR::GC('x*x+a',{x,a[1]})");

   // Compiled and interpreted functions (rather than p.d.f.s) can be made with the lower case
   // 'expr' and 'cexpr' types

   // Print workspace contents
   w->Print();

   // Make workspace visible on command line
   gDirectory->Add(w);
}