Int_t testFoam(){
   gSystem->Load("libFoam");
   TH2D  *hst_xy = new TH2D("hst_xy" ,  "x-y plot", 50,0,1.0, 50,0,1.0);
   Double_t *MCvect =new Double_t[2]; // 2-dim vector generated in the MC run
   TRandom3  *PseRan   = new TRandom3();  // Create random number generator
   PseRan->SetSeed(4357);                // Set seed
   TFoam   *FoamX    = new TFoam("FoamX");   // Create Simulator
   FoamX->SetkDim(2);          // No. of dimensions, obligatory!
   FoamX->SetnCells(500);      // No. of cells, can be omitted, default=2000
   FoamX->SetRhoInt(Camel2);   // Set 2-dim distribution, included below
   FoamX->SetPseRan(PseRan);   // Set random number generator
   FoamX->Initialize();        // Initialize simulator, takes a few seconds...
   // From now on FoamX is ready to generate events according to Camel2(x,y)
   for(Long_t loop=0; loop<100000; 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;
     hst_xy->Fill(x,y);           // fill scattergram
   }// loop
   Double_t mcResult, mcError;
   FoamX->GetIntegMC( mcResult, mcError);  // get MC integral, should be one
   cout << " mcResult= " << mcResult << " +- " << mcError <<endl;
   // now hst_xy will be plotted visualizing generated distribution
   TCanvas *cKanwa = new TCanvas("cKanwa","Canvas for plotting",600,600);
   cKanwa->cd();
   hst_xy->Draw("lego2");
 }//kanwa
 Double_t sqr(Double_t x){return x*x;};
 Double_t Camel2(Int_t nDim, Double_t *Xarg){
 // 2-dimensional distribution for FOAM, normalized to one (within 1e-5)
   Double_t x=Xarg[0];
   Double_t y=Xarg[1];
   Double_t GamSq= sqr(0.100e0);
   Double_t Dist=exp(-(sqr(x-1./3) +sqr(y-1./3))/GamSq)/GamSq/TMath::Pi();
   Dist        +=exp(-(sqr(x-2./3) +sqr(y-2./3))/GamSq)/GamSq/TMath::Pi();
   return 0.5*Dist;
 }// Camel2