> Dear Root,
> Is it possible to plot member functions? The following does not work:
>
> class RtRelation
> {
> public:
> double rmin,rmax;
> double* Rt(double * x, double* par);
> }
>
> RtRelation* rtrelation = new RtRelation;
> TF1* rt = new TF1("rt",rtrelation->Rt,
> rtrelation->rmin,rtrelation->rmax,0);
>
> If it is possible, how should I do it ?
> Regards, thanks, Wouter
No, an input parameter for TF1 cannot be a class member function.
See list of possibilities in http://root.cern.ch/root/html/TF1.html
You can only define a normal function like in the example below.
Inside this function, you can use a global pointer to access
one of your objects and invoke its member function.
Rene Brun
Double_t Rt(Double_t *x, Double_t *par)
{
Double_t arg = 0;
if (par[2]) arg = (x[0] - par[1])/par[2];
Double_t fitval = par[0]*TMath::Exp(-0.5*arg*arg);
return fitval;
}
void myfunc()
{
// Creates a Root function based on function Rt above
TF1 *func = new TF1("Rt",Rt,-2,2,3);
// Sets initial values and parameter names
func->SetParameters(100,0,1);
func->SetParNames("Constant","Mean_value","Sigma");
func->Draw();
}