13

I am trying to export a list of text strings from Python to MATLAB using scipy.io. I would like to use scipy.io because my desired .mat file should include both numerical matrices (which I learned to do here) and text cell arrays.

I tried:

import scipy.io
my_list = ['abc', 'def', 'ghi']
scipy.io.savemat('test.mat', mdict={'my_list': my_list})

In MATLAB, I load test.mat and get a character array:

my_list =

adg
beh
cfi

How do I make scipy.io export a list into a MATLAB cell array?

1
  • 2
    You might also be interested in my python-in-MATLAB project: github.com/kw/pymex Commented Mar 12, 2010 at 16:44

2 Answers 2

13

You need to make my_list an array of numpy objects:

import scipy.io
import numpy as np
my_list = np.zeros((3,), dtype=np.object)
my_list[:] = ['abc', 'def', 'ghi']
scipy.io.savemat('test.mat', mdict={'my_list': my_list})

Then it will be saved in a cell format. There might be a better way of putting it into a np.object, but I took this way from the Scipy documentation.

Sign up to request clarification or add additional context in comments.

1 Comment

For posterity: an easier way to make an object array is np.asarray(['abc', 'def', 'ghi'], dtype='object').
1

It looks like the contents of the list are exported properly, they are just transposed and placed in a character array. You can easily convert it to the desired cell array of strings in MATLAB by transposing it and using CELLSTR, which places each row in a separate cell:

>> my_list = ['adg';'beh';'cfi'];  %# Your example
>> my_list = cellstr(my_list')    %'# A 3-by-1 cell array of strings

my_list = 

    'abc'
    'def'
    'ghi'

Granted, this doesn't address the more general issue of exporting data as a cell array from Python to MATLAB, but it should help with the specific problem you list above.

Comments

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.