How to pass a structure from Matlab to Python

I'm using Matlab(2014b) and Python(2.7.6) for mix programming. I tried to pass a structure from Matlab to Python,but I failed.

The structure I want to pass is:

   dmodel = struct('regr',regr, 'corr',corr, 'theta',theta.', ...
    'beta',fit.beta, 'gamma',fit.gamma, 'sigma2',sY.^2.*fit.sigma2, ...
    'S',S, 'Ssc',[mS; sS], 'Ysc',[mY; sY], ...
    'C',fit.C, 'Ft',fit.Ft, 'G',fit.G);

In the structure all the elements are scalar except Ssc and Ysc.

The Matlab script looks like this:

function model=Fun_mat()
   ...
   some command;
   ...
   model = dmodel;
end

and the Python script looks like this:

import matlab.engine as meng
eng = meng.start_matlab()
dmodel = eng.Fun_mat()
eng.quit()

These two scripts are in the same directory.

What should I do? Any help is appreciate!

Answer 1

[Gareth Thomas]

Hi Jason,

Have you seen this page in the R2015a documentation:

MathWorks Documentation: Handle Data returned from MATLAB to Python

Please note that this is used for the MATLAB engine which can be called from python. I hope that this helps you.

Best regards, Gareth

[Jason Shih]

Hi Gareth,

Thanks for your reply. I have read that document before, but I still have some problems.

The structure I want is

dmodel = 
      regr: 1
      corr: 2
     theta: [0.4419 0.1091]
      beta: [6x1 double]
     gamma: [1x100 double]
    sigma2: 949.8115
         S: [100x2 double]
       Ssc: [2x2 double]
       Ysc: [2x1 double]
         C: [100x100 double]
        Ft: [100x6 double]
         G: [6x6 double]

(I'm sorry I was wrong about the element type before.)

The problem is that when Matlab return the struture with element 'C'(a 100*100 double matrix), I get the messeage below in Python:

Segmentation fault (core dumped)

But when the Matlab return the structre without the element 'C', I get no error in Python.

What should I do?

Best regards, Jason

Answer 2

[Jason Shih]

I have figured out what's wrong in that script. The element 'C' in the structure in a sparse matrix, which in not supported by the engine now.