Re: TGraphErrors

Hi,

that code does not correspond to the error you have sent before.

You cannot call a virtual function on a NULL pointer - that's basic C++. If you don't know what that means then you will have to learn C++, e.g. by reading an introduction + tutorials. There are several on the web.

Cheers, Axel.

Ijaz Ahmed wrote on 09/22/2010 01:33 PM:
>
> Hi..
> I am using GetMeanError method of TH1F class and SetPointError method of TGraphError class as below:
> ********
>
> TH1F* fVertexZTPC=0x0;
>
> fVzMeanTPC->SetPoint(npoint, runs[i], fVertexZTPC->GetMean());
>
> fVzMeanTPC->SetPointError(npoint, 0, fVertexZTPC->GetMeanError());
>
>
>
> Ij az Ahmed
> CIIT, Islamabad
> mob#+923345349527
> URL: http://iahmed.web.cern.ch/iahmed
>
>
>
> -----Original Message-----
> From: Olivier Couet
> Sent: Wed 9/22/2010 1:04 PM
> To: Ijaz Ahmed; roottalk (Mailing list discussing all aspects of the ROOT system.)
> Subject: RE: [ROOT] TGraphErrors
>
> Hi,
> GetMeanError is not a method of TGraphErrors. See the list of TGraphErrors' methods here:
> http://root.cern.ch/root/html/TGraphErrors.html
> Cheers,
> Olivier
> -----Original Message-----
> From: owner-roottalk_at_root.cern.ch [mailto:owner-roottalk_at_root.cern.ch] On Behalf Of Ijaz Ahmed
> Sent: Wednesday, September 22, 2010 12:57 PM
> To: roottalk (Mailing list discussing all aspects of the ROOT system.)
> Subject: [ROOT] TGraphErrors
>
> Hi...
>
> I am getting the following error during compiling my root macro. Anybody can guess what going on wrong with it?.
> *************************
> Error: Can't call TGraphErrors::GetMeanError() in current scope readQAgrid_tracks.C:228:
> Possible candidates are...
> (in TGraphErrors)
> (in TGraph)
> *** Interpreter error recovered ***
>
> Ijaz Ahmed
> CIIT, Islamabad
> mob#+923345349527
> URL: http://iahmed.web.cern.ch/iahmed
>
>
>
>
>
>
>
Received on Wed Sep 22 2010 - 14:26:18 CEST