Re: number axis values plotted

On Fri, 26 May 2006, Rene Brun wrote:

> h[0] = new TH1F("h1", "h1", 10, 0, 10);
> h[0]->GetXaxis()->SetNdivisions(505);
>
> I strongly suggest to use the graphics editor to check quickly
> the best settings.

Hi Rene,
thanks, now I finally understand how this Ndivisions is decomposed! I was too stupid to understand (or too lazy while reading) the documentation...

But now I stumble over the fact that it is not done in the same way for TGaxis as it is done for TAxis: For TGaxis I cannot switch off the optimisation: There is no bool as second argument for TGaxis::SetNDivisions(..) and negative values seem to stop root.

See the attached macro where I try to plot a TGaxis for an axis from 0 to 180 with 6 main divisions (guess which quantity it is...)

I tested on ROOT 4.04.02 and 5.10.00.

Cheers

        Gero  

> On Fri, 26 May 2006, flucke_at_mail.desy.de wrote:
>
> > Dear ROOTers,
> > is there a way to control the number of axis values plotted?
> >
> > In the attached example I would like to have only the values 0, 2, 4, 6,
> > 8 and 10 plotted next to the axis of the first histogram whose axis
> > ranges from 0 to 10. Having all integer values from 0 to 6 on an axis from
> > 0 to 6 (second histogram) is fine.
> > As you can see, I found a small trick (third histogram), but that does not
> > solve my general problem that I sometimes want to divide the umber of
> > plotted lables by two.
> > I did not manage with TAxis->SetNdivisions(...) ...
> >
> > Cheers
> >
> > Gero