Rajat,
You forgot to draw the function. See the NEW LINE in your code below
The TF1 internal histogram is only created when the function is drawn.
You can do directly:
TF1* identity = new TF1("identity", "1", 0., 10.);
identity->Draw();
Rene Brun
On Fri, 5 Jul 2002, Rajat Bhatnagar wrote:
> Hi,
>
> I'm trying to use the TH1::GetHistogram() method to get a histogram fitted
> to a certain formula. Using the simplest case I could think of, I tried
>
> root [0] TF1* identity = new TF1("identity", "1", 0., 10.);
> root [1] TCanvas c_new;
identity->Draw(); //<==============NEW LINE
> root [2] TH1F* idH = (TH1F*) identity->GetHistogram();
> root [3] idH->Draw();
> Error: illegal pointer to class object idH 0x0 136
> FILE:/tmp/fileAGKUbL_cint LINE:1
> *** Interpreter error recovered ***
>
> but got the error above. Any suggestions on what to do?
>
> Also, I noticed that if a TCanvas does not already exist, there is a
> segmentation violation. Does anyone have thoughts on how to work around
> this?
>
> Thanks,
> Raj Bhatnagar
>
>
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:50:59 MET