Hi Marc,
Thanks for reporting this problem.
Now fixed by Olivier Couet in the development version in CVS
Rene Brun
On Wed, 10 Jul 2002, Marc Brueggemann wrote:
> Hi everybody,
>
> I realized a problem with drawing option "E3" to draw a colored error
> band. It occurs if I apply this option to a histogram which also
> contains empty bins and using the method 'SetMinimum()' simultaneously.
> Starting from the last bins the error band is focused to the origin.
> A strange fragment occurs.
>
> I have reduced the problem to a little macro which you can try out.
> It contains two loops for filling a histogram with errors. One loop
> leaves the first bins empty the other (uncomment it) fills
> all bins.
>
>
>
> Int_t Test(){
>
> TH1F* h_test = new TH1F("h_test","h_test", 45, 0, 12 );
>
> // for (Int_t i = 1; i <= 45; ++i) { // use this loop and no problem
> // occurs (because no empty bins are present)
> for (Int_t i = 6; i <= 45; ++i) {
> h_test->SetBinContent(i, 4.0);
> Float_t error = (40.1-i)/40.0;
> h_test->SetBinError(i, error);
> }
>
> TCanvas* canvas = new TCanvas("canvas", "canvas", 1);
> h_test->SetMinimum(0.01);
> h_test->SetMaximum(6);
> h_test->SetFillColor(kRed);
> h_test->Draw("E3");
> h_test->Draw("P HIST SAME");
>
>
> return 0;
> }
>
>
> The same fragment occurs if I don't use 'SetMinimum()' but afterwards
> (if I can see the histogram in a canvas)
> try to zoom into a certain region of the y-axis.
>
>
> The question: Does this problem also occur if you try this
> macro?
>
> Am I doing something wrong?? How can I keep ROOT from connecting the
> error band with the origin ???
>
> I'm using ROOT-version 3.02/02
> (I also tried version 2.24/05 and the same problem occured)
>
>
>
> Best regards
>
> Marc Brueggemann
>
> --
> Marc Brueggemann mailto:bruegge@Physik.Uni-Dortmund.DE
> Experimentelle Physik Vb phone: +49 (231) 755 3667
> Dortmund University
> D-44227 Dortmund
>
>
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