{
gROOT->ProcessLine(".L brem.C+");
double zrad=79;
double arad=197;
double radln=0.0003;
double radlength=716*arad/(zrad*zrad*log(183.*pow(zrad,-1/3)));
double trad=radln*radlength;

//fbrem=photon(eelec,egam,trad,zrad,arad);
double ebeam = 1700.;
double ebeam1 = 1600.;
double ratio = 0.4;
double yy[110];
double yy1[110];
double xx[110];
for(int i =0; i<110; i++)
{
  xx[i]=ebeam*(1.-ratio*(1-i/100.));
  yy[i]=photon(ebeam,xx[i],trad,zrad,arad);
  yy1[i]=photon(ebeam1,xx[i],trad,zrad,arad);
  //  cout<<ebeam<<" "<<xx[i]<<endl;
}
TGraph* gr1 = new TGraph(110,xx,yy);
gr1->SetMinimum(0);
gr1->Draw("APL");
TGraph* gr2 = new TGraph(110,xx,yy1);
gr2->SetMinimum(0);
gr2->Draw("PL");
}