rendering a plot changes its dimensions [was: graphics_array messes up dimensions of plots]

[pdehaye]

The following code should illustrate this, see picture below, everything gets scaled for no reason.

graph = circle((0,0),20)
graph.set_aspect_ratio(1)
graph2 = graphics_array([[graph]*4]*4)
graph2.show()

The real reason is that axes_pad<>0 will affect the same picture every time it's rendered (to be saved or displayed), and change its dimensions by 2% each time by default. I can understand the need for axes_pad, but don't think this should happen:

graph = circle((0,0),20)
graph.show()
print graph.get_axes_range()
graph.save('test.png')
graph.save('test.png')
graph.save('test.png')
graph.save('test.png')
graph.save('test.png')
print graph.get_axes_range()
graph.show()

and compare with

graph = circle((0,0),20)
graph.show(axes_pad=0)
print graph.get_axes_range()
graph.save('test.png',axes_pad=0)
graph.save('test.png',axes_pad=0)
graph.save('test.png',axes_pad=0)
graph.save('test.png',axes_pad=0)
graph.save('test.png',axes_pad=0)
print graph.get_axes_range()
graph.show(axes_pad=0)

Component: graphics

Keywords: axes_range, axes_pad

Author: Paul Dehaye

Issue created by migration from https://trac.sagemath.org/ticket/8019

[pdehaye]

comment:1

Attachment: circles.png

[pdehaye]

Changed keywords from graphics_array, scale to axes_range, axes_pad

[jasongrout]

comment:3

I think the problem is that in the save routine (actually, in the .matplotlib() method), the x and y limits are changed according to the axes_pad setting. Instead, they should be temporarily changed and then changed back so that the graphic has the same x and y limits as it did when starting.

[mwhansen]

comment:4

This has been fixed by #10291.