Davrot at 16:59, 17 October 2025

2025-10-17T16:59:47Z

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	~~== The goal ==~~
	We want to integrate Python files and code into our Matlab workflow.		We want to integrate Python files and code into our Matlab workflow.

Davrot: Created page with "== The goal == We want to integrate Python files and code into our Matlab workflow. Questions to [mailto:davrot@uni-bremen.de David Rotermund] == Check if you are ready == [https://de.mathworks.com/support/requirements/python-compatibility.html Versions of Python Compatible with MATLAB Products by Release] You need to ask yourself or better Matlab if it is using the correct Python. You can check this via:>> pyenv ans = PythonEnviron..."

2025-10-17T14:05:05Z

Created page with "== The goal == We want to integrate Python files and code into our Matlab workflow. Questions to [mailto:davrot@uni-bremen.de David Rotermund] == Check if you are ready == [https://de.mathworks.com/support/requirements/python-compatibility.html Versions of Python Compatible with MATLAB Products by Release] You need to ask yourself or better Matlab if it is using the correct Python. You can check this via:<syntaxhighlight lang="matlab">>> pyenv ans = PythonEnviron..."

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== The goal ==
We want to integrate Python files and code into our Matlab workflow.

Questions to [mailto:davrot@uni-bremen.de David Rotermund]

== Check if you are ready ==
[https://de.mathworks.com/support/requirements/python-compatibility.html Versions of Python Compatible with MATLAB Products by Release]

You need to ask yourself or better Matlab if it is using the correct Python. You can check this via:<syntaxhighlight lang="matlab">>> pyenv

ans =

PythonEnvironment with properties:

Version: "3.11"
Executable: "/data_1/davrot/P3.11/bin/python3"
Library: "libpython3.11.so.1.0"
Home: "/data_1/davrot/P3.11"
Status: NotLoaded
ExecutionMode: InProcess
</syntaxhighlight>If this is wrong (which it isn’t in my case) then you can change it (temporarily?) with<syntaxhighlight lang="matlab">>> pyenv('Version','/data_1/davrot/P3.11/bin/python3')

ans =

PythonEnvironment with properties:

Version: "3.11"
Executable: "/data_1/davrot/P3.11/bin/python3"
Library: "libpython3.11.so.1.0"
Home: "/data_1/davrot/P3.11"
Status: NotLoaded
ExecutionMode: InProcess</syntaxhighlight>'''Obviously you need to use your location for your Python installation.'''

== Python help ==
<syntaxhighlight lang="matlab">>> py.help('int')
Help on class int in module builtins:

class int(object)
| int([x]) -> integer
| int(x, base=10) -> integer
[...]</syntaxhighlight>

== Tuple and random number example ==
We can crate a python tuple like this:<syntaxhighlight lang="matlab">>> py_dim = py.tuple({py.int(10), py.int(100)})

py_dim =

Python tuple with values:

(10, 100)

Use string, double or cell function to convert to a MATLAB array.</syntaxhighlight>Now we can use numpy to generate random numbers:<syntaxhighlight lang="matlab">>> py_dim = py.tuple({py.int(10), py.int(100)})
>> rng = py.numpy.random.default_rng();
>> a = rng.random(py_dim);
>> py.print(py.type(a))
<class 'numpy.ndarray'>
>> py.print(a.shape)
(10, 100)
>> py.print(a.dtype)
float64
>> whos
>> whos
Name Size Bytes Class Attributes

a 1x1 8 py.numpy.ndarray
ans 1x1 8 matlab.pyclient.PythonEnvironment
py_dim 1x2 8 py.tuple
rng 1x1 8 py.numpy.random._generator.Generator </syntaxhighlight>Alternatively this is also possible:<syntaxhighlight lang="matlab">>> b = rng.random(cell({int32(10),int32(100)}));</syntaxhighlight>

== User defined Python modules ==
Our very own Python function in the file '''mtest_1.py''':<syntaxhighlight lang="python">import numpy as np

def mysquared(input:np.ndarray) -> np.ndarray:
output = input**2
return output</syntaxhighlight>Now Matlab allows us to do this:<syntaxhighlight lang="matlab">>> x = (1:1:10);
>> x_np = py.numpy.array(x);
>> y_np = py.mtest_1.mysquared(x_np);
>> y = double(x_np).^2;
>> sum(sum(abs(y-double(y_np))))

ans =

0</syntaxhighlight>If you change the py file, then you need to clean it from the memory via<syntaxhighlight lang="matlab">>> clear classes</syntaxhighlight>Future David here: Well, I had to do this for a file gauss_smear.py with a function gauss_smear:<syntaxhighlight lang="matlab">if ~exist('mod', 'var')
mod = py.importlib.import_module('gauss_smear');
end

py.importlib.reload(mod);

clearvars -except mod
mod.gauss_smear(2.0, 0.1)</syntaxhighlight>

== Save a numpy file with Matlab ==
In Matlab we save data into numpy file:<syntaxhighlight lang="matlab">>> a = rand(100,10);
>> a_np = py.numpy.array(a);
>> py.numpy.save("test_1.npy",a_np);</syntaxhighlight>Now we can load it into Python:<syntaxhighlight lang="python">import numpy as np

a = np.load("test_1.npy")

print(type(a)) # --> <class 'numpy.ndarray'>
print(a.shape) # --> (100, 10)
print(a.dtype) # --> float64</syntaxhighlight>

== Loading a numpy file with Matlab ==
Under Python we generate a file:<syntaxhighlight lang="python">import numpy as np

myrng = np.random.default_rng()

a = myrng.random((100, 10))
np.save("test_2.npy", a)</syntaxhighlight>And under Matlab we load it:<syntaxhighlight lang="matlab">>> a_np = py.numpy.load("test_2.npy");
>> a = double(a_np);
>> whos
Name Size Bytes Class Attributes

a 100x10 8000 double
a_np 1x1 8 py.numpy.ndarray </syntaxhighlight>

== References ==

* [https://de.mathworks.com/help/matlab/matlab_external/create-object-from-python-class.html Access Python Modules from MATLAB - Getting Started]
* [https://de.mathworks.com/help/matlab/matlab_external/pythonstrvariables.html Use Python str Variables in MATLAB]
* [https://de.mathworks.com/help/matlab/matlab_external/pythonlistvariables.html Use Python list Variables in MATLAB]
* [https://de.mathworks.com/help/matlab/matlab_external/pythontuplevariables.html Use Python tuple Variables in MATLAB]
* [https://de.mathworks.com/help/matlab/matlab_external/python-dict-variables.html Use Python dict Variables in MATLAB]
* [https://de.mathworks.com/help/matlab/matlab_external/call-user-defined-custom-module.html Call User-Defined Python Module]

Running Python remotely from Matlab - Revision history

Davrot at 16:59, 17 October 2025