ROOT 6.32.00: ulast > fXmax, fXmax is used message

[LeWhoo]

Dear All,

I have a program that displays a 2D histogram with some margins:

To achieve that, I do:

pdm.GetXaxis().SetRangeUser(-1, self.ExpTree.MaxHistoPixelX+1)

and the same on Y. On the most recent ROOT, I started to get warnings:

TAxis::TAxis::SetRangeUser:0: RuntimeWarning: ufirst < fXmin, fXmin is used
TAxis::TAxis::SetRangeUser:0: RuntimeWarning: ulast > fXmax, fXmax is used
TAxis::TAxis::SetRangeUser:0: RuntimeWarning: ufirst < fXmin, fXmin is used
TAxis::TAxis::SetRangeUser:0: RuntimeWarning: ulast > fXmax, fXmax is used

The first point is, that new ROOT versions will not force me to create a bigger histogram with an empty border, because that will complicate the histogram filling (bin by bin and replacing its underlying array) significantly and make it bug prone.

Second, I think that the warning is… not telling the truth, because the margins are there

How should I proceed?

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ROOT Version: 6.32.02
Platform: Fedora 40
Compiler: linuxx8664gcc

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[Danilo]

Hi,

I am sorry you are experiencing this behaviour. I add in the loop @couet .

Cheers,
D

[couet]

Can you provide a small script reproducing this issue ?

[LeWhoo]

auto h = new TH2D("h", "h", 2, 0, 2, 2, 0, 2)
h->GetXaxis()->SetRangeUser(-1, 3)
h->Draw("colz")

[couet]

I see. With SetRange or SetRangeUser, you generally cannot define larger ranges than the initial ones. @moneta can confirm this.

[LeWhoo]

I thought so, but it works. It seems like a bug was an important functionality for me, and the bug (that I actually can define larger ranges, and it works; it just complains) still exists. Would it be possible to keep it or add some functions to do what I am doing—adding “margins” to the histogram inside the histogram frame?

For now I can filter the warning in Python, but I am afraid you will fix the bug (first time in my long history of using ROOT I am afraid of that ).

[couet]

I am not sure it is working when you see the SetRange code.
@moneta can tell more on that.

[LeWhoo]

Hello,

Any update on that issue?

[couet]

@moneta is the expert for this part of the code.

[LeWhoo]

Trying to keep this topic alive.