[Python-talk] SWIG tips? Howto?

[Kent Johnson]

On Tue, Aug 18, 2009 at 9:37 PM, Bruce
Labitt<bruce.labitt at myfairpoint.net> wrote:
> Kent Johnson wrote:
>>
>> On Tue, Aug 18, 2009 at 3:07 PM, <bruce.labitt at autoliv.com> wrote:

>>> I have used FFTW before (www.fftw.org) for my work.  How hard would it be
>>> to use SWIG to wrap a few FFTW routines to hopefully speed up the FFTs?
>>>
>>
>> Google is your friend...
>> http://developer.berlios.de/projects/pyfftw/
>> http://www.nabble.com/FFTW-python-bindings-again-td21676636.html
>
> Looks like there are some warts still.  Memory alignment for one thing.  May
> still be worth pursuing.

You would have the same issues if you were to roll your own, I think...


>> or you could communicate through sockets...
>>
>
> Just looked at that.  This would very cool.

You might be able to find some kind of socket server for the QS22 to
help you get started with the code.
>
> Once the connection was established, I need to send the array length N, then
> the data.  It is not clear to me how to send an array of N binary complex
> double precision numbers, from a little endian to a big endian machine over
> a socket.  I could send them as strings, but that a) would not be as precise
> and b) take at least twice as long.

Use the Python struct module to generate the array in the byte-order you need.

> If all the data was there, then the algorithm would run.  When complete the
> QS22 would send the data to a python socket that was listening on my server.
>  Could the python socket be controlled by paramiko?  Or would I use another
> module?

The python socket would be part of your main program. The only need
for paramiko would be to start the remote process that listens for
data requests.

Kent