rf503_wspaceread.C

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/// \file
/// \ingroup tutorial_roofit
/// \notebook -js
///  'ORGANIZATION AND SIMULTANEOUS FITS' RooFit tutorial macro #503
///
///  Reading and using a workspace
///
///  --> The input file for this macro is generated by rf502_wspaceread.C
///
/// \macro_image
/// \macro_output
/// \macro_code
/// \author 07/2008 - 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"
#include "TFile.h"
#include "TH1.h"
using namespace RooFit ;


void rf503_wspaceread()
{
   // R e a d   w o r k s p a c e   f r o m   f i l e
   // -----------------------------------------------

   // Open input file with workspace (generated by rf14_wspacewrite)
   TFile *f = new TFile("rf502_workspace.root") ;

   // Retrieve workspace from file
   RooWorkspace* w = (RooWorkspace*) f->Get("w") ;



   // R e t r i e v e   p d f ,   d a t a   f r o m   w o r k s p a c e
   // -----------------------------------------------------------------

   // Retrieve x,model and data from workspace
   RooRealVar* x = w->var("x") ;
   RooAbsPdf* model = w->pdf("model") ;
   RooAbsData* data = w->data("modelData") ;

   // Print structure of composite p.d.f.
   model->Print("t") ;


   // F i t   m o d e l   t o   d a t a ,   p l o t   m o d e l 
   // ---------------------------------------------------------

   // Fit model to data
   model->fitTo(*data) ;
   
   // Plot data and PDF overlaid
   RooPlot* xframe = x->frame(Title("Model and data read from workspace")) ;
   data->plotOn(xframe) ;
   model->plotOn(xframe) ;

   // Overlay the background component of model with a dashed line
   model->plotOn(xframe,Components("bkg"),LineStyle(kDashed)) ;

   // Overlay the background+sig2 components of model with a dotted line
   model->plotOn(xframe,Components("bkg,sig2"),LineStyle(kDotted)) ;



   // Draw the frame on the canvas
   new TCanvas("rf503_wspaceread","rf503_wspaceread",600,600) ;
   gPad->SetLeftMargin(0.15) ; xframe->GetYaxis()->SetTitleOffset(1.4) ; xframe->Draw() ;


}