Re: [Matplotlib-users] Agg backend in Windows

[John H. <jdh...@ac...>]

>>>>> "Dominique" == Dominique Orban <do...@da...> writes:

    Dominique> Just wanted to signal some path issues with the current
    Dominique> Windows installer. I have looked in the mailing list,
    Dominique> but haven't seen anyone having the same problem.

    Dominique> In both Windows 2000 and XP, installation of Matplotlib
    Dominique> 0.50 results in the following directory hierarchy in my
    Dominique> main Python directory c:\Python23\Lib\site-packages
    Dominique> (Enthought Edition):

    Dominique>   FontTools/ fontTools/ sstruct.py ttLib/

Critically, you should also have
c:\Python23\Lib\site-packages\FontTools.pth.  I am pretty certain it
is in the windows installer.  This file should contain one line, which
reads simply 

FontTools

If you don't have it I would like to know!  

ttfquery and FontTools are packages to enable cross platform
font-finding.  I am very interested in factoring out this dependency
since it complicates installation (as you are seeing).  [ Perry, if
anyone in your group is still interested in this, there is a
reasonably well documented example in cvs examples/ftface_props.py
that shows how to access all the relevant freetype attributes (family
name, is italics, etc) using the matplotlib.ft2face module ]

    Dominique> it says it cannot import 'fontTools' (lowercase f,
    Dominique> uppercase T).  Changing the name of the top directory
    Dominique> (FontTools) to 'fontTools' doesn't solve it of course,
    Dominique> since what it is looking for is the innermost
    Dominique> one. Hence i must move the 'fontTools' directory one
    Dominique> level up. Next, it can import ttLib, scans my TTFPATH,
    Dominique> but breaks down (after litterally one zillion messages)
    Dominique> saying that 'module' has no attribute 'SFNTReader'. It
    Dominique> is in fact trying to import sfnt and is stuck in the
    Dominique> __init__() of Class TTFont. Drastically reducing my
    Dominique> TTFPATH, i see that the error is in fact coming from
    Dominique> the fact that it cannot import module 'sstruct' in
    Dominique> sfnt.py.

All of this is consistent with a missing FontTools.pth.  ttfquery will
try and load each windows font, but catches all exceptions and
continues.  So you'll get an exception *for each font* the first time
you load ttfquery if something is wrong with your install.  After you
have fixed fontools, be sure to remove site-packages/font.cache so
ttfquery can regenerate the font cache.

    Dominique> That stuns me. A 'from fontTools import sstruct' would
    Dominique> do. How comes Python isn't looking recursively into
    Dominique> directories? I guess moving everything to the top level
    Dominique> isn't a good idea. Also, still in sfnt.py, the 'import
    Dominique> struct' works, but i have no clue where it finds this
    Dominique> one; a search was unsuccessful. Anyhow, including
    Dominique> 'c:\Python23\fontTools' into the PYTHONPATH solves it
    Dominique> but i thought directories would be parsed recursively.

    Dominique> Also, can you only use savefig() with the Agg backend?
    Dominique> show() isn't popping any window.

Agg is a pure image backend - ie, it only produces image output.  In
the next release of matplotlib (this week) there will are 2 GUI
backends that use agg for rendering GtkAgg and TkAgg, both of which
are compiled into the windows installer.

    Dominique> As they told me to at SuSE, i'm having a lot of fun.

You mean battling the hairy windows beast?

JDH