scikit-hep/root_numpy

Import of root_numpy somehow uses a canvas?

jonas-eschle opened this issue · 3 comments

jonas-eschle commented

Hi there,

I just came across some strange behavior, which I think is not intended.

A simple plot (or only canvas drawing) in python:

from ROOT import RooRealVar
from ROOT import TCanvas <- this "solves" the problem
import root_numpy <- this produces the "bug"
x = RooRealVar("x", "x variable", 5000, 6000)
xframe = x.frame()
xframe.Draw()

It works and the canvas shows up if we omit the second and third line.
Using also the root_numpy import-statement will result in no drawing but two warnings instead and no canvas will be shows:

TCanvas::ResizePad:0: RuntimeWarning: c1 width changed from 0 to 10
TCanvas::ResizePad:0: RuntimeWarning: c1 height changed from 0 to 10

First importing TCanvas too before importing root_numpy resolves the problem.
I am not sure how this is caused and whether it is a problem, but it's a strange behavior.
What do you think?

My specs:

  • Python 2.7
  • root-numpy 4.5.2
  • ROOT 5.34/30 (the Ubuntu-repository version with bindings)
  • Ubuntu 16.04
ndawe commented

root_numpy doesn't use TCanvas anywhere. I'm not sure what the problem is. I see the canvas pop up with and without the root_numpy import.

ndawe commented

Although I'm using ROOT 6.06.02. Could be some obscure problem with 5.34.30

jonas-eschle commented

Ok, thanks for you investigation! As it seems not to occur on later versions and as there is a "hack" available, I close this issue.