Calling MATLAB functions from python

Question

I know this is an old question and has been answered. But I was looking for the same thing (for the Mac) and found that there are quite a few options with different methods of interacting with matlab and different levels of maturity. Here's what I found:

pymat

A low level interface to Matlab using the matlab engine (libeng) for communication (basically a library that comes with matlab). The module has to be compiled and linked with libeng.

http://pymat.sourceforge.net
Last updated: 2003

pymat2

A somewhat short lived continuation of the pymat development. Seems to work on windows (including 64bit), linux and mac (with some changes).

https://code.google.com/p/pymat2/
Last updated: 2012

mlabwrap

A high level interface that also comes as a module which needs compilation and linking against libeng. It exposes Matlab functions to python so you can do fun stuff like

mlab.plot(x, y, 'o')

http://mlabwrap.sourceforge.net
Last updated: 2009

mlab

A repackaging effort of mlabwrap. Basically it replaces the c++ code that links against 'libeng' in mlabwrap with a python module (matlabpipe) that communicates with matlab through a pipe. The main advantage of this is that it doesn't need compilation of any kind.

Unfortunately the package currently has a couple of bugs and doesn't seem to work on the mac at all. I reported a few of them but gave up eventually. Also, be prepared for lots of trickery and a bunch of pretty ugly hacks if you have to go into the source code ;-) If this becomes more mature it could be one of the best options.

https://github.com/ewiger/mlab
last update: 2013

pymatlab

A newer package (2010) that also interacts with Matlab through libeng. Unlike the other packages this one loads the engine library through ctypes thus no compilation required. Its not without flaws but still being maintained and the (64bit Mac specific) issues I found should be easy enough to fix.
(edit 2014-05-20: it seems those issues have already been fixed in the source so things should be fine with 0.2.4)

http://pymatlab.sourceforge.net
last update: 2014

python-matlab-bridge

Also a newer package that is still actively maintained. Communicates with Matlab through some sort of socket. Unfortunately the exposed functions are a bit limited. I couldn't figure out how to invoke a function that takes structs as parameters. Requires zmq, pyzmq and IPython which are easy enough to install.

http://arokem.github.io/python-matlab-bridge
last update: 2014

Another option is Mlabwrap:

Mlabwrap is a high-level python to Matlab® bridge that lets Matlab look like a normal python library.

It works well with numpy arrays. An example from the home page:

>>> from mlabwrap import mlab; from numpy import *
>>> xx = arange(-2*pi, 2*pi, 0.2)
>>> mlab.surf(subtract.outer(sin(xx),cos(xx)))

PyMat looks like it's been abandoned.

I'm assuming you are on windows so you could always do the simplest approach and use Matlab's COM interface:

>>> import win32com.client
>>> h = win32com.client.Dispatch('matlab.application')
>>> h.Execute ("plot([0 18], [7 23])")
>>> h.Execute ("1+1")
u'\nans =\n\n     2\n\n'

More info here

There is a python-matlab bridge which is unique in the sense that Matlab runs in the background so you don't have the startup cost each time you call a Matlab function. https://github.com/jaderberg/python-matlab-bridge

it's as easy as downloading and the following code:

from pymatbridge import Matlab
mlab = Matlab(matlab='/Applications/MATLAB_R2011a.app/bin/matlab')
mlab.start()
res = mlab.run('path/to/yourfunc.m', {'arg1': 3, 'arg2': 5})
print res['result']

where the contents of yourfunc.m would be something like this:

%% MATLAB
function lol = yourfunc(args)
    arg1 = args.arg1;
    arg2 = args.arg2;
    lol = arg1 + arg2;
end