Hi David, Did you have a look at mlabwrap? It's quite hard to find on the net, which is a shame, since it is a much more up to date version, enhancing pymat with the things that you are trying to do. It allows passing arrays and getting arrays back.
http://mlabwrap.sourceforge.net/ However, I do agree with you that it would be good to have a bridge based on ctypes. I can't really help since I long ago moved all of my code from Matlab to Numpy and Matplotlib. Cheers, Josh M David Cournapeau <[EMAIL PROTECTED]> wrote: > > Hi, > > I am trying to find a nice way to communicate between matlab and > python. I am aware of pymat, which does that, but the code is > deprecated, and I thing basing the code on ctypes would lead to much > more robust code. > > http://claymore.engineer.gvsu.edu/%7Esteriana/Software/pymat.html > > I have a really simple prototype which can send and get back data from > matlab, but I was wondering if it would be possible to use a scheme > similar to ctypes instead of having to convert it by hand. Let me > present the way communication with matlab is done: > > - open a matlab session, which on unix launch a matlab process, > and > set up pipes between the calling process and matlab process for > communication > - To send data from the calling process to matlab, you first > have to > create a mxArray, which is the basic matlab handler of a matlab array, > and populating it. Using mxArray is very ackward : you cannot create > mxArray from existing data, you have to copy data to them, etc... > (it is > one of the reason I started looking in python in the first place: > interfacing matlab with foreign code is really not a nice experience, > and the API is not rich enough to do many interesting things; I am > actually amazed how poor this part of matlab is, a product which is > now > 20 years old). > > I was wondering if there was a way to extend a numpy array so > that I > could send directly numpy arrays to matlab C functions expecting a , > with ctypes doing the hard work. For example, now, to send data to > matlab, I do: > > session = MatlabEngine() > # data is a numpy array, 'dataname' a string with its name inside > matlab interpreter > session.put(data, 'dataname') > > The put function has do to a lot for work: > - first, getting metadata from data (dimensions, real or complex, > etc...) > - then creating a mxArray with the same metadata > - then populating the mxarray by copying the data from the > numpy array. > > And of course, taking care that all mxarrays are detroyed, otherwise, > memory leak... That's why I was thinking about something a bit > smarter: > creating a mxarray class which implements the numpy interface. I could > create a mxarray from a numpy array easily, send a mxarray directly > to C > function with ctypes, etc... Is this doable ? Would this take care of > correct destruction of mxarrays ? I really don't know much about the > internals of numpy arrays, so I don't really know how to start, > > cheers, > > David > > ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Numpy-discussion mailing list Numpy-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/numpy-discussion
