Re: [Visualpython-users] Python 2.5

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

On Fri, 2006-10-06 at 12:40 -0600, Bruce Sherwood wrote:
> Questions have been asked about Visual for Python 2.5. A significant 
> hurdle to overcome is that there is not and will not be a version of 
> Numeric for Python 2.5 (the last to be made was for Python 2.4). Its 
> successor Numarray does exist for Python 2.5 but is likely to be the 
> last, as the download instructions say "Use Numpy!"

The last time that I looked, the Numpy documentation was only available
for a fee.  That is why Visual was not extended to support it last
summer.  At any rate, the person(s) who decide to add support for Numpy
to VPython should see below.

>  Thanks to Jonathan 
> Brandmeyer's work, Visual can be compiled for Numarray, but some 
> existing VPython programs that used explicit Numeric capabilities may 
> break due to some incompatibilities between Numeric and Numarray.
> 
> The right thing to do is to revise Visual to use Numpy, which is the 
> designated to-be-supported replacement for both Numeric and Numarray. I 
> do not know how much work will be required to do this.

The revision effort should not be too difficult, as there is an
abstraction layer for Numeric/Numarray in VPython.  Basically, at
startup-time, a set of function pointers are initialized that refer to
either the Numarray or Numeric implementations.  Additionally,
Boost.Python support for the two libs is selected at run-time.

The affected files are:
VPython 3.x:
src/num_util_impl_numeric.cpp
src/num_util_impl_numarray.cpp
src/num_util.cpp
include/num_util_impl.hpp
include/num_util.hpp

The VPython 4.x files are setup in exactly the same way, except that
they are found in src/python and include/python.

See also site-packages/visual/array_backend.py in both versions,
although I think that there is a cleaner way to go about what this file
does.

Lastly, there are some configure script elements that would need to be
updated in acinclude.m4 (specifically, VISUAL_NUMERICLIBS).

HTH,
-Jonathan