[Matplotlib-users] Upgraded to 1.1.0, now only line graphs work!

[John L. <joh...@sb...>]

Two days ago I posted some questions about upgrading, and was pointed to
the right resources by some readers who replied to me privately
(thanks!).  I am running Python 2.6 on an Ubuntu Linux 10.10 platform.
The upgrade appeared to build successfully, but I still have problems.

Line graphs appear to be working all right, but images and contour
graphs generate errors, and fail to draw.


My procedure:

I deleted every last old matplotlib-related file from my hard disk,from
both my Python dist-packages directory and from my home directory.  I
got my build dependencies up to date, and installed using git as
described here:

http://matplotlib.sourceforge.net/faq/installing_faq.html#install-from-git


The three-line simple_plot.py script suggested here...

http://matplotlib.sourceforge.net/faq/installing_faq.html

...runs, displays a line graph, and outputs the following when run with
the flag --verbose-helpful:

17:26:42 -> python simple_plot.py --verbose-helpful
$HOME=/home/john
CONFIGDIR=/home/john/.matplotlib
matplotlib data
path /usr/local/lib/python2.6/dist-packages/matplotlib/mpl-data
loaded rc
file /usr/local/lib/python2.6/dist-packages/matplotlib/mpl-data/matplotlibrc
matplotlib version 1.2.x
verbose.level helpful
interactive is False
platform is linux2
Using fontManager instance from /home/john/.matplotlib/fontList.cache
backend GTKAgg version 2.21.0
findfont:
Matching :family=sans-serif:style=normal:variant=normal:weight=normal:stretch=normal:size=medium to Bitstream Vera Sans (/usr/local/lib/python2.6/dist-packages/matplotlib/mpl-data/fonts/ttf/Vera.ttf) with score of 0.000000


Now, here's a very simple script of mine, which should draw a figure
with a colored bulls-eye:

from numpy import exp, fromfunction, hypot
import matplotlib.pyplot as plt
    
def func(x, y):
    return exp(-hypot(x-50,y-50) / 20)

fig = plt.figure()
ax = plt.subplot(111)
arr = fromfunction(func, (101,101))
img = plt.imshow(arr)
plt.show()


Instead, it draws an empty figure, and returns a long and
apparently-repeated traceback, which I hesitate to post in its entirety.
Here's the last repeat.  I believe that I got this eight times in a row:

Traceback (most recent call last):
  File
"/usr/local/lib/python2.6/dist-packages/matplotlib/backends/backend_gtk.py", line 418, in expose_event
    self._render_figure(self._pixmap, w, h)
  File
"/usr/local/lib/python2.6/dist-packages/matplotlib/backends/backend_gtkagg.py", line 75, in _render_figure
    FigureCanvasAgg.draw(self)
  File
"/usr/local/lib/python2.6/dist-packages/matplotlib/backends/backend_agg.py", line 400, in draw
    self.figure.draw(self.renderer)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/figure.py",
line 886, in draw
    func(*args)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/axes.py", line
1983, in draw
    a.draw(renderer)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/image.py",
line 356, in draw
    im = self.make_image(renderer.get_image_magnification())
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/image.py",
line 576, in make_image
    transformed_viewLim)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/image.py",
line 202, in _get_unsampled_image
    x = self.to_rgba(self._A, bytes=True)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/cm.py", line
215, in to_rgba
    x = self.cmap(x, alpha=alpha, bytes=bytes)
  File "/usr/local/lib/python2.6/dist-packages/matplotlib/colors.py",
line 521, in __call__
    cbook._putmask(xa, xa==1.0, np.nextafter(xa.dtype.type(1),
AttributeError: 'module' object has no attribute 'nextafter'


Programs which invoke contour() instead of imshow() fail similarly.  I
downloaded the 1.1.0 animation examples (my whole reason for upgrading
was to use the new animation methods), and only the line-graph examples
work.


As suggested (on a page I can't quite track down now), I captured a log
of the build and install commands.  The words "error" or "warning" do
not show up in either of those logs -- and I did get several warnings
when building 0.99 and 1.0.1, so I feel like things ought to be working
better this time, not worse...

Thanks for any hints!