Using Matlab in Python

Hello,

I'm trying to execute matlab functions in python using the Matlab python package. However, when running an example from the documentation, I am getting an error message. When I run the code:

import matlab
import matlab.engine
eng = matlab.engine.start_matlab()
a = matlab.double([1,4,9,16,25])
b = eng.sqrt(a)
print(b)

I get the error message:

File "<ipython-input-7-6ccc095b323c>", line 1, in <module>
  runfile('/Users/rach/Google Drive/PHD/Programming/Winds/Trying.py', wdir='/Users/rach/Google Drive/PHD/Programming/Winds')

File "//anaconda/envs/netcdf/lib/python2.7/site-packages/spyder/utils/site/sitecustomize.py", line 866, in runfile
  execfile(filename, namespace)

File "//anaconda/envs/netcdf/lib/python2.7/site-packages/spyder/utils/site/sitecustomize.py", line 94, in execfile
  builtins.execfile(filename, *where)

File "/Users/rach/Google Drive/PHD/Programming/Winds/Trying.py", line 4, in <module>
  a = matlab.double([1,4,9,16,25])

File "//anaconda/envs/netcdf/lib/python2.7/site-packages/matlab/mlarray.py", line 51, in __init__
  raise ex

TypeError: 'NoneType' object is not callable

What does this error mean? Is it something to do with how I have installed everything?

Thanks, Rachael

Answer 1

[Nagarjuna Manchineni]

Looking at the error message, I can see that you are using the python from the Anaconda distribution. This version of Python is not supported with MATLAB. CPython is the recommended Python distribution for use with MATLAB Engine for Python, as noted at the following links:

http://www.mathworks.com/help/matlab/matlab_external/system-requirements-for-matlab-engine-for-python.html http://www.mathworks.com/help/matlab/matlab_external/install-supported-python-implementation.html

I believe once you install the correct version you will not encounter the same issue.

[Rachael Hardman]

Ahh I see... Thank you. I have got it to work with my version - I just have to restart the kernal everytime I want to run the code. It's definitely not ideal but got my code to work!

[Juan Salcedo]

Can you elaborate. I am also using the Anaconda thing and want to run Matlab commands

[Seth Wagenman]

This answer makes MATLAB work with a conda environment:

https://www.mathworks.com/matlabcentral/answers/443558-matlab-crashes-when-using-conda-environment-other-than-base#answer_486374