Hi,

I think I've found a bug in matplotlib 0.53. The bug can be triggered

with the following commands

from matplotlib.matlab import *

plot(arange(40), array([1]*40))

show()

Basically, bad things happen if you try to plot a flat line. By

themselves, flat lines aren't very interesting, but they do occasionally

show up in the automated graphing batches I do. The first problem is an

easily patched bug in ticker.py where matplotlib tries to take the

logarithm of the interval span of the input data. For a constant data

series, that interval span is zero, and log(0) is naturally unhappy.

Unfortunately, after fixing that problem, another problem arises. In

transformer.py, a divide by zero is triggered when trying to determine

display scale for much the same reason.

I've patched these bugs as best I can, but my fix isn't worth much since

the results look awful (no tick marks, data is uncentered). Its probably

best to let someone who knows what they're doing fix this for real.

Thanks a lot,

Mike Salib