Comment 0 for bug 1398818

La version compilable de myfunc.C (p.27) devrait être:

#include "TF1.h"
#include "TH1.h"
#include "TROOT.h" // <============= missing!

Double_t myfunction(Double_t *x, Double_t *par)
{
 Float_t xx = x[0];
 Double_t f = TMath::Abs(par[0]*sin(par[1]*xx)/xx);
 return f;
}
void makefunc()
{
   TF1* f1 = new TF1("func",myfunction,0,10,2);
   f1->SetParameters(2,1);
   f1->SetParNames("constant", "coefficient");
   f1->Draw();
}
void myfit()
{
   TH1F* h1 = new TH1F("h1","test",100,0,10);
   h1->FillRandom("func",20000);
   TF1* f1 = (TF1*)gROOT->GetFunction("func"); // <======== gROOT->GetFunction renvoie TObject*, not TF1* !
   f1->SetParameters(800,1);
   h1->Fit("func");
}