[Visualpython-users] Numpy compatibility

[Arthur <ajs...@op...>]

Folks,

I have now  - I believe - successfully implemented a VPython that is 
compatible with the final 1.0 release of the numpy library.

I have tried to do so touching as little of the existing code as 
possible, hoping to avoid the possibility of inadvertently introducing 
bugs into the code in this process. In fact the most radical surgery to 
the existing code is a simplification - i.e. removing code and logic 
that was there only to allow for the build against the *both* Numeric 
and numarray libraries and the selection of one or the other as a 
preference.  My code assumes a build against numpy, and only numpy.

As hoped, there wasn't all that more that needed to be done to get the 
basic compatibility issues resolved beyond what could be learned from 
Phil Austin's approach in moving his num_util  helper functions for 
boost::python::numeric arrays (used in the current vpython release) to 
numpy compatibility.

See.

http://www.eos.ubc.ca/research/clouds/software/pythonlibs/num_util/num_util_release2/

The only problems I have had running the demos and my own code that 
utilizes vpython is in differences between the Numeric and numpy Python 
APIs. For example numpy wants a lower case type identifier, e.g."float", 
rather than as upper case "Float" when creating an array with a type 
identifier.

Numpy does have an "oldnumeric.py" library whose purpose - as the name 
implies - is to add a compatibility layer between numpy and the older 
numeric libraries at the Python coding level.. It is trivial to have 
that library load as part of the start-up of vpython.  For my purposes, 
I want to begin to understand the numpy library better, and having the 
incompatibilities fall out is helpful, so I have not done so.  But Bruce 
might want to include it in the vpython start-up routines, at least 
during some transition period.

What I have. *not* done is accomplish the changes to the build mechanism 
that are necessary to detect the numpy library as part of the configure 
routine and to create the proper Makefile or issue the appropriate 
messages in case of its failure to do so.  I have simply been manually 
editing the Makefile for the few changes necessary to build against numpy.

My interest in learning more about the vpython, boost and numpy 
internals, and get more hands on with C++ in general, made this little 
numpy compatibility effort on my part something I enjoyed, being 
compatible with my more general personal objectives.  Dealing with the 
build issues would be less so.So I am hoping someone else will step up 
to the plate.  OTOH, the necessary changes are probably not hard to 
accomplish, and if no one else does, I will try to get to it.

Bruce,

What next?

Art