reading v 7.3 mat file in python

Question

I am trying to read a matlab file with the following code

import scipy.io
mat = scipy.io.loadmat(\'test.mat\')

and it gives me the followin

Answer 1

Despite hours of searching I've not found how to access Matlab v7.3 structures either. Hopefully this partial answer will help someone, and I'd be very happy to see extra pointers.

So starting with (I think the [0][0] arises from Matlab giving everything to dimensions):

f = h5py.File('filename', 'r')
f['varname'][0][0]

gives: < HDF5 object reference >

Pass this reference to f again:

f[f['varname'][0][0]]

which gives an array: convert this to a numpy array and extract the value (or, recursively, another < HDF5 object reference > :

np.array(f[f['varname'][0][0]])[0][0]

If accessing the disk is slow, maybe loading to memory would help.

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Further edit: after much futile searching my final workaround (I really hope someone else has a better solution!) was calling Matlab from python which is pretty easy and fast:

eng = matlab.engine.start_matlab()  # first fire up a Matlab instance
eng.quit()
eng = matlab.engine.connect_matlab()  # or connect to an existing one
eng.sqrt(4.0)
x = 4.0
eng.workspace['y'] = x
a = eng.eval('sqrt(y)')
print(a)
x = eng.eval('parameterised_function_in_Matlab(1, 1)', nargout=1)
a = eng.eval('Structured_variable{1}{2}.object_name')  # (nested cell, cell, object)