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Reference Guide
foam_demopers.C File Reference

Detailed Description

View in nbviewer Open in SWAN This simple macro demonstrates persistency of FOAM object.

First run macro foam_demo.C to create file foam_demo.root with FOAM object.

Next type root -l foam_demopers.C from shell command line

#include "Riostream.h"
#include "TFile.h"
#include "TFoam.h"
#include "TROOT.h"
#include "TSystem.h"
#include "TFoamIntegrand.h"
Int_t foam_demopers()
// need to load the foam_demo tutorial for the definition of the function
TString macroName = gROOT->GetTutorialDir();
gROOT->ProcessLine(TString::Format(".L %s+",macroName.Data()));
cout<<"====================== TestVector ================================"<<endl;
TFile fileA("foam_demo.root");
TFoam *FoamX = (TFoam*)fileA.Get("FoamX");
// FoamX->PrintCells();
//N.B. the integrand functions need to be reset
// because cannot be made persistent
TFoamIntegrand * rho = (TFoamIntegrand*) gROOT->ProcessLine("return new TFDISTR();");
Double_t MCvect[2]; // 2-dim vector generated in the MC run
for(long loop=0; loop<50000; loop++){
FoamX->MakeEvent(); // generate MC event
FoamX->GetMCvect( MCvect); // get generated vector (x,y)
Double_t x=MCvect[0];
Double_t y=MCvect[1];
if(loop<10) cout<<"(x,y) = ( "<< x <<", "<< y <<" )"<<endl;
}// loop
Double_t IntNorm, Errel;
FoamX->Finalize( IntNorm, Errel); // final printout
Double_t MCresult, MCerror;
FoamX->GetIntegMC( MCresult, MCerror); // get MC integral, should be one
cout << " MCresult= " << MCresult << " +- " << MCerror <<endl;
cout<<"===================== TestPers FINISHED ======================="<<endl;
return 0;
int Int_t
Definition: RtypesCore.h:45
double Double_t
Definition: RtypesCore.h:59
#define gROOT
Definition: TROOT.h:404
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition: TFile.h:54
Abstract class representing n-dimensional real positive integrand function.
Definition: TFoamIntegrand.h:9
TFoam is the main class of the multi-dimensional general purpose Monte Carlo event generator (integra...
Definition: TFoam.h:21
virtual void CheckAll(Int_t)
User utility, miscellaneous and debug.
Definition: TFoam.cxx:1382
virtual void GetMCvect(Double_t *)
User may get generated MC point/vector with help of this method.
Definition: TFoam.cxx:1176
virtual void MakeEvent()
User method.
Definition: TFoam.cxx:1126
virtual void GetIntegMC(Double_t &, Double_t &)
User method.
Definition: TFoam.cxx:1211
virtual void SetRho(TFoamIntegrand *Rho)
User may use this method to set the distribution object.
Definition: TFoam.cxx:1022
virtual void Finalize(Double_t &, Double_t &)
May be called optionally by the user after the MC run.
Definition: TFoam.cxx:1260
Basic string class.
Definition: TString.h:136
const char * Data() const
Definition: TString.h:369
TString & Append(const char *cs)
Definition: TString.h:564
static TString Format(const char *fmt,...)
Static method which formats a string using a printf style format descriptor and return a TString.
Definition: TString.cxx:2336
Double_t y[n]
Definition: legend1.C:17
Double_t x[n]
Definition: legend1.C:17
Stascek Jadach

Definition in file foam_demopers.C.