Why matlab crashes when I try to use a numpy Python package? (2019a)

I'm trying to use Python on Matlab, but the system crashes everytime I try to use a Numpy Package.

My only step was to switch the pyversion to match with anaconda executable version (I'm on Linux):

pyversion

       version: '3.7'
    executable: '/home/rubem/anaconda3/bin/python'
       library: '/home/rubem/anaconda3/lib/libpython3.7m.so'
          home: '/home/rubem/anaconda3'
      isloaded: 0

If a type something like:

      py.importlib.import_module('numpy')

or:

      py.numpy.limspace(0,10,101)

Matlab crashes. In the Terminal, the following command appear:

      malloc(): memory corruption
/usr/local/bin/matlab: line 3:  1874 Segmentation fault      sudo /usr/local/Polyspace/R2019a/bin/matlab

Despite the lack of documentation on Matlab, I tried to find out what the hell was going on and I found out two interesting things:

1 - I followed the example in https://www.mathworks.com/help/matlab/matlab_external/call-user-defined-custom-module.html and it's works. So I Think that just the numpy package has the problem

2 - If I type

py.sys.path

I recieve:

ans = 

  Python list with no properties.

    ['', '/home/rubem/anaconda3/lib/python37.zip', '/home/rubem/anaconda3/lib/python3.7', '/home/rubem/anaconda3/lib/python3.7/lib-dynload', '/home/rubem/anaconda3/lib/python3.7/site-packages']

That's weird because the second one isn't a path folder (python37 is a .zip-file that doesn't exist). Unfortunately, I don't know how I can change this.

3 - "isloaded" is equal to zero when the matlab initialize. I don't know neither how I set this logical variable nor what is this does (I swear for god I searched, but the documentation on Matlab is very poor yet).

How can I solve this problem?

Answer 1

[Rubem Pacelli]

I think the problem was my program. I switched to 2018b and it seems to work.

btw, I think its more useful to close this post because the problem wasn't technical questions.

[Pierre Loicq]

I resolved the exact same problem on Matlab 2016b with this one : https://fr.mathworks.com/matlabcentral/answers/358233-matlab-python-interface-broken

Answer 2

[Hiro Yoshino]

This might be useful:

https://jp.mathworks.com/matlabcentral/answers/410406-import-numpy-to-matlab

[Rubem Pacelli]

Unfortunately nothing helped me. Theses instructions should make sense for Windows user, It's no my case.

Even so, thanks for your help.

[Hiro Yoshino]

How about updating your MATLAB?

[Rubem Pacelli]

Hiro Yoshino I'm using matlab from university, it's not up to me.

[Hiro Yoshino]

Look like your Python has not been properly loaded in the first place.

isloaded is supposed to be 1 if it is loaded:

https://jp.mathworks.com/help/matlab/ref/pyversion.html#buei1xf-1-isloaded

You should re-set it up again by following:

https://jp.mathworks.com/help/matlab/matlab_external/system-and-configuration-requirements.html

[Hiro Yoshino]

This might be helpful:

https://www.youtube.com/watch?v=y7NBT6O0fJU

[Rubem Pacelli]

Hiro Yoshino, i saw all yours links.

1 - The command "pyenv" seems don't exist on 2019a.

Undefined function or variable 'pyenv'

2 - According to what I read: "MATLAB automatically selects and loads a Python version when you type a Python command, such as: py.funcname" . I did it. I created a silly .py-function called "my_python_function.py" and I call it from matlab. It's work because I don't use numpy package. Then, I typed pyversion and I recieve:

version: '3.7'
    executable: '/home/rubem/anaconda3/bin/python'
       library: '/home/rubem/anaconda3/lib/libpython3.7m.so'
          home: '/home/rubem/anaconda3'
      isloaded: 1

however, If I type then

      py.importlib.import_module('numpy')

My matlab crashes anyway :(

Answer 3

[Hiro Yoshino]

Read the documentation for R2019a. You might have counted on the latest. It might be a cause of the problem.

Sometimes, there exists slight difference across the versions.

https://jp.mathworks.com/help/releases/R2019a/index_ja_JP.html

[Rubem Pacelli]

Hiro Yoshino, I read this. Unfortunately, nothing there help to solve my problem

Answer 4

[Hiro Yoshino]

https://www.youtube.com/watch?v=aJGmnPfJBuo

Have you ever tried this ? - calling MATLAB from the anaconda prompt?