[Matplotlib-users] Req: Matplotlib compatibility problem - help please!

Hi folks

I am teaching myself Python by working 
through Hans Petter Langtangen's 
excellent book "Primer on Scientific 
Programming in Python".

The exercises in chapter 4 of the book 
require the student to use Python with 
the freely downloadable tools 
MatplotLib and SciTools to plot graphs 
of mathematical functions.

Despite downloading and installing 
numerous different versions of Python 
2.x, MatPlotLib and SciTools, I am 
unable to find a combination which 
will work together without crashing.

I'm currently using a Windows XP 
laptop with:
Python 2.6.6
IDLE 2.6.6
MatplotLib 0.99,3 win32 Py2.6
Scitools from 
scipy-0.80-win32-superpack-python 2.6

When I try to run a simple script to 
test the plotting functions, I get the 
error messages attached below.

I don't want to use Python 3, as there 
still seem to be some teething 
problems with this, and many of the 
modules that I've already written or 
need to use are not compatible with 
Python 3.x.

I've emailed the author, but have not 
yet had a reply.

I'd be very grateful if you could 
explain why I get the error messages 
shown below, what is a compatible 
combination of versions of Python 2.x, 
MatPlotLib and Scitools; and the URL 
of sites where I can download these.

Many thanks in anticipation


Dave
(UK)

=============================
Test script:

    1. from scitools.std import *
    2.
    3. def f(t):
    4.     return t**2*exp(-t**2)
    5.
    6. t = linspace(0,3,51)
    7. y = zeros(len(t))
    8. for i in xrange(len(t)):
    9.     y[i] = f(t[i])
   10.
   11. plot(t,y)
   12.
   13.

===============================

>>>
scitools.easyviz backend is matplotlib

Traceback (most recent call last):
File "C:\Python\Dave_Book 
Exercises\4_3_2 Plot test_DW.py", line 
11, in <module>
plot(t,y)
File 
"C:\Python26\lib\site-packages\scitools\easyviz\common.py", 
line 3060, in plot
self._replot()
File 
"C:\Python26\lib\site-packages\scitools\easyviz\matplotlib_.py", 
line 906, in _replot
self._g.draw()
File 
"C:\Python26\lib\site-packages\matplotlib\pyplot.py", 
line 352, in draw
get_current_fig_manager().canvas.draw()
File 
"C:\Python26\lib\site-packages\matplotlib\backends\backend_tkagg.py", 
line 215, in draw
FigureCanvasAgg.draw(self)
File 
"C:\Python26\lib\site-packages\matplotlib\backends\backend_agg.py", 
line 314, in draw
self.figure.draw(self.renderer)
File 
"C:\Python26\lib\site-packages\matplotlib\artist.py", 
line 46, in draw_wrapper
draw(artist, renderer, *args, 
**kwargs)
File 
"C:\Python26\lib\site-packages\matplotlib\figure.py", 
line 773, in draw
for a in self.axes: a.draw(renderer)
File 
"C:\Python26\lib\site-packages\matplotlib\artist.py", 
line 46, in draw_wrapper
draw(artist, renderer, *args, 
**kwargs)
File 
"C:\Python26\lib\site-packages\matplotlib\axes.py", 
line 1735, in draw
a.draw(renderer)
File 
"C:\Python26\lib\site-packages\matplotlib\artist.py", 
line 46, in draw_wrapper
draw(artist, renderer, *args, 
**kwargs)
File 
"C:\Python26\lib\site-packages\matplotlib\axis.py", 
line 742, in draw
tick.draw(renderer)
File 
"C:\Python26\lib\site-packages\matplotlib\artist.py", 
line 46, in draw_wrapper
draw(artist, renderer, *args, 
**kwargs)
File 
"C:\Python26\lib\site-packages\matplotlib\axis.py", 
line 196, in draw
self.label1.draw(renderer)
File 
"C:\Python26\lib\site-packages\matplotlib\text.py", 
line 518, in draw
bbox, info = 
self._get_layout(renderer)
File 
"C:\Python26\lib\site-packages\matplotlib\text.py", 
line 280, in _get_layout
clean_line, self._fontproperties, 
ismath=ismath)
File 
"C:\Python26\lib\site-packages\matplotlib\backends\backend_agg.py", 
line 148, in 
get_text_width_height_descent
texmanager = self.get_texmanager()
File 
"C:\Python26\lib\site-packages\matplotlib\backend_bases.py", 
line 374, in get_texmanager
from matplotlib.texmanager import 
TexManager
File 
"C:\Python26\lib\site-packages\matplotlib\texmanager.py", 
line 72, in <module>
class TexManager:
File 
"C:\Python26\lib\site-packages\matplotlib\texmanager.py", 
line 94, in TexManager
_dvipng_hack_alpha = 
dvipng_hack_alpha()
File 
"C:\Python26\lib\site-packages\matplotlib\texmanager.py", 
line 68, in dvipng_hack_alpha
raise RuntimeError('Could not obtain 
dvipng version')
RuntimeError: Could not obtain dvipng 
version
>>>