RE: TH2F & drawing curve

From: Nevzat Guler <nguler_at_jlab.org>
Date: Wed, 28 Nov 2007 12:28:07 -0500 (EST)

	Hello,
	Actually I think there is no way for what I want to do with the

TH2 so I am converting all my TH2 objects into TGraph. with TGraph I can just use Draw("L") which will draw line through the points..

        But if you want to investigate more just for curiosity, I explained more below:

        My data looks like ( an example )
bin# value

1     23
2     24
3     26
4     32
5     27
6     25
7     23
8     21
9     19

Then I define TH2F and fill it and draw it:

TH2F *2D = new TH2F(rname,"",40,80.,150.,500,0.,500.); 2D->Fill(bin, value[bin]);
2D->Draw();

This actually looks looks like one dimensional gaussian histogram but created as TH2 object. (because of the format of the data)

So, my conclusion is that there is no drawing option for this that will simply draw line through the data points. I suppose it is because the format of the data is more suitable for TGraph instead of TH2..

        Thanks, Best regards.

                                Nevzat Guler

On Wed, 28 Nov 2007, Olivier Couet wrote:

> I am not sure to really understand the kind of plot you would like. From
> a TH2 it seems difficult to draw a 2d curve . what will be the x and y
> coordinates of the points ?
>
> -----Original Message-----
> From: Nevzat Guler [mailto:nguler_at_jlab.org]
> Sent: Tuesday, November 27, 2007 7:35 PM
> To: Olivier Couet
> Cc: Root Group
> Subject: RE: [ROOT] TH2F & drawing curve
>
>
> Thanks. But I wanted 2 dimensional curve on 2 dimensional plot.
> A simplified example:
>
> TH2F *2D = new TH2F(rname,"",40,80.,150.,500,0.,500.);
> 2D->Fill(w, count[w]);
> 2D->Draw("same");
>
> This looks something like a gaussian dist. But only points..
> I want to connect these points with line, or I only want to plot it as a
> line. The "surf" option converts it to a 3D picture..
> Best regards,
>
> Nevzat Guler
>
> On Tue, 27 Nov 2007, Olivier Couet wrote:
>
> > Hi,
> >
> > That's the option SURF.
> >
> > Cheers, O.Couet
> >
> > -----Original Message-----
> > From: owner-roottalk_at_root.cern.ch [mailto:owner-roottalk_at_root.cern.ch]
> > On Behalf Of Nevzat Guler
> > Sent: Tuesday, November 27, 2007 4:31 AM
> > To: Root Group
> > Subject: [ROOT] TH2F & drawing curve
> >
> >
> > Hello,
> > Is there a drawing option for 2D histogram (TH2F) that draws
> > curve
> > through data points? (like the option "C" in TH1F..)
> > I could not find any such option in the list. Basically I can convert
> > the
> > histogram into a TGraph object but I am looking for an easy way out..
> > Thanks for the helps..
> >
> > Nevzat Guler
> >
> >
> >
>
>
Received on Wed Nov 28 2007 - 18:28:29 CET