Re: very slow drawing

Rene Brun (Rene.Brun@cern.ch)
Fri, 05 Feb 1999 16:58:39 +0000

Thomas Walter wrote:
>
> Dear rooters,
>
> my root-macro executes very fast until it reaches the part,
> where the postscript file is generated. The cpu-usage drops
> from about 99% to less then 3%.
>
> I'm using root 2.0.13, intel linux, libc 5.
>
> Here is the critical part of the macro:
>
> c1->cd();
> hpad->Draw();
> tpad->Draw();
> for(t = 0; t < 50; t++) {
> tt = aH * t;
> sprintf(titleName, "Tracking %s Helix %s Thresold %d Meth %d",
> runName, SelHelix, t+thresmin, tracMeth);
> padText.SetTitle(titleName);
> tpad->cd();
> ps->NewPage();
> padText->Draw();
> for ( i = 0; i < 7; i++) {
> hpad->cd(i+1);
> gPad->Clear();
> ((TH1F*)(myHs[i+tt]))->Draw("");
> }
> hpad->cd(8);
> myHt1->Draw("");
> c1->Update();
> }
>
> What is my mistake?
>

Thomas,
In this part of the macro, you draw 400 histograms. This may take a long
time
depending how many channels you have per histogram and your options.
Is your Postcript file generated on an AFS disk?
What is the size of the generated ps file?

Rene Brun