Re: TGraph constructor

From: Rene Brun (Rene.Brun@cern.ch)
Date: Fri May 15 1998 - 10:04:08 MEST


Wouter Hulsbergen wrote:
> 
> Dear all,
> I have got a question with regard to the TGraph constructor:
> 
>  TGraph::TGraph(Int_t n, Float_t *x, Float_t *y)
>        : TNamed("Graph","Graph"), TAttLine(), TAttFill(), TAttMarker()
> {
> //*-*-*-*-*-*-*-*-*-*-*Graph normal
> constructor-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
> //*-*                  ========================
> 
>    if (n <= 0) {
>       Error("TGraph", "illegal number of points (%d)", n);
>       return;
>    }
> 
>    fFunctions = new TList(this);
>    fHistogram = 0;
>    fNpoints   = n;
>    fX         = new Float_t[n];
>    fY         = new Float_t[n];
>    fMaximum   = -1111;
>    fMinimum   = -1111;
>    if (!x || !y) return;
>    for (Int_t i=0;i<n;i++) {
>       fX[i] = x[i];
>       fY[i] = y[i];
>    }
> }
> 
> It looks to me as if the contructor checks if `x' and `y' are NULL
> pointers (?). This would be quite nice if they were also default
> arguments, such that I can construct a TGraph, without given x and y.
> However, in the header file I cannot find the default arguments. Is there
> something wrong? Is it alright if I just add default arguments in the
> headerfile ?
> 
> Regards,
> Wouter

I had already made this change in the development version.
This version 2.00/06 will appear late today or tomorrow morning.

Rene Brun



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