Re: [Visualpython-users] Experimental Windows version for Python 2.4

[Jonathan B. <jbr...@ea...>]

On Tue, 2004-12-28 at 11:48 -0500, Bruce Sherwood wrote:
> Now available at vpython.org is an experimental version of VPython for 
> Python 2.4 on Windows. The only known bug is that programs that use the 
> "text" module to display block letters (including the demo programs 
> stonehenge.py and texttest.py) fail on some but not all computers. We 
> would appreciate feedback on this or other bugs you may find. This was 
> built using the new Boost-based package created by Jonathan Brandmeyer.
> 


There is one additional change that this release has versus prior
releases that used Boost.Python for its bindings.  This build supports
and includes both Numeric 23.6 and Numarray 1.1.1.

By default, executing "from visual import *" will bring in Numeric, and
not Numarray, and will use Numeric arrays to hold the data of curves,
convex, and faces objects.  You can alter this behavior by calling the
function set_array_backend() with either the string "numeric" or
"numarray".  To be safe, you should only do this once at the beginning
of your program, before creating any array-using objects.  If you are
forcing the use of Numarray in this way, you must also run "from
numarray import *".  It is not safe to change the backend after you have
created a visual object that uses an array (even if its pos, color, or
normal attribute appears to be empty).

Alternatively, you can edit site-packages/visual/__init__.py (lines
16-23) to change the preference for all applications on your particular
installation.

I intend to provide support for Numeric as long as it is supported
upstream and not too much of a burden on Visual.  Numarray has very good
backwards compatibility with Numeric, and Visual's core works exactly
the same with both.  However, there are some differences which you may
see in your own programs (some of our demos are also affected).  So,
Visual will prefer Numeric by default rather than Numarray, for maybe 6
months to a year, depending on feedback from you and the development of
Numeric/Numarray.

-Jonathan Brandmeyer

P.S.  The source package for Linux and OSX will be released soon (to be
versioned 3.1.0).  I am working out a few kinks in the configuration and
build control files.