Error: negative operand

Hello Rooters,

This macro:

void str(){
  // define stretched exponential
  Double_t stretched(Double_t *x,Double_t *par)     {

      Double_t fitval = par[0]*TMath::Exp((-x[0]/par[1])**par[2]);
      //      Double_t fitval = par[0] + par[1]*x[0];
      return fitval;

  TCanvas *can = new TCanvas("can","90040 stretched");

  TF1 *func = new TF1("func", stretched, 1,300, 3);   func->SetParameters(184.87,44.69,0.87);   // func->SetParameters(1,10);
  func->Draw();

  can->Update();
}

generates this:

root [0] .x str.C
Error: operator '@' or '**' negative operand str.C:3:

with the last line repeated many times.

Can someone explain what I've done wrong?

root 5.14/00 gentoo linux.

Thanks,

Roger Received on Thu Mar 08 2007 - 21:31:14 CET