Get maximum of a function

[kanhaiya-gupta]

Hi,
I want to calculate the maxima of a function. But when I apply the below code it gives the highest value of x in the range ( 4 here in the macro). Can you please tell me how to do it.

TF1 *f3 = new TF1(“f3”,“f0/f1”,0,4.); // Division of two functions
Double_t c = f3->GetMaximumX(); //GetXmax();
std::cout << "c = "<< c << std::endl;

The answer I get is c = 4. The analytical answer of 1.02.

Thank you

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[Wile_E_Coyote]

I’m not sure what you mean. Try:

{
  TF1 *f3 = new TF1("f3", "TMath::DiLog(x)", 0., 10.);
  f3->Draw();
  Double_t c = f3->GetMaximumX();
  std::cout << "c = "<< c << std::endl;
  std::cout << "f3(c) = "<< f3->Eval(c) << std::endl;
  std::cout << "f3 maximum = "<< f3->GetMaximum() << std::endl;
}