[Numpy-discussion] Options for wrapping C and C++ code for use with Numeric

Chris Barker Chris.Barker at noaa.gov
Thu Nov 3 12:08:55 EST 2005

Hi all,

I suddenly seem to have the need for working with a bunch of different 
existing C and C++ code, so I'm looking for a way to make it easier. I 
love NumPy, so I really want to use NumPy arrays  My needs fall into 
three categories:

1) Writing custom extension code from scratch:

In the past, I've done this by just using the NumPy API, but it seems 
that I shouldn't have to do all that book keeping myself.

2) Wrapping existing libraries:

At the moment, I'd like to wrap Richard Shewchuk's triangle:


Which is straight C, as well as the Proj4 map projections library, also 
C, and there may be others.

3) Wrapping in house code, C & C++, that is under development, but I 
want to be able to use it from Python and C++, and also perhaps to write 
tests for it in Python.

The options I'm looking at are:


This seems like perhaps the easiest way to write extension code, but it 
doesn't do any automatic wrapping.


This looks like a very nice way to write extension modules, and it even 
appears to already include support for NumPy arrays (which ones? is that 
support being maintained, and will it support SciPy.base?)


The has the major advantage of automatically wrapping code. I see this 
as a particular strength for wrapping our in house code that is under 
development. In theory, once I've written a bunch of type maps, i can 
just re-run it whenever the code base changes.

For each of these, I'd love to hear what people's experiences have been, 
and it would be great if anyone can point me to samples that are small 
but non-trivial. Other options I should consider would be great too.

One more question: Should I use NumPy arrays to pass data back and forth 
between Python and C, or should I use the new array object/protocol 
instead? If so, has anyone developed examples, SWIG type maps, etc for this?

Thanks for any feedback,


Christopher Barker, Ph.D.
NOAA/OR&R/HAZMAT         (206) 526-6959   voice
7600 Sand Point Way NE   (206) 526-6329   fax
Seattle, WA  98115       (206) 526-6317   main reception

Chris.Barker at noaa.gov

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