I get an error when using numpy in my python script in simulink

I try to use a python script (version 3.11 according to the pyenv command) as a function in simulink. I use python importer and it works fine when not using numpy. As soon as I start the script with 'import numpy as np' however, the blocks don't work anymore and I get the error:

MATLAB System block 'Mytester21/taketwo2_CreateArrayfivedim' error occurred when invoking 'setupImpl' method of 'taketwo2_CreateArrayfivedim'.

Caused by:

• Invalid HandleObjectRef - Entry not found in the server table

Component:Simulink | Category:Block error

The python script itself does not matter, as this issue arises with various different python files. Can anyone help me with this?

(an additional issue that I have is that I need to restart my computer every time I rework something in the python file, an update through obj.view does not update the simulink output.)

[Bastiaan]

Fixed it

[Rajat Kumar Raghav]

Hello Bastiaan,

I am also facing the same issue as mentioned above, but even with simple code for adding 2 numbers.

Please find the code below.

Can you please tell me how you fixed it.

def sum2ints(var1, var2):
    sum_int = var1 + var2
    print(sum_int)
    return sum_int


if __name__ == '__main__':
    num1 = int(input('Enter the number1: '))
    num2 = int(input('Enter the number 2: '))
    output = sum2ints(num1, num2)
    print('Final output is : ', output)

[Rajat Kumar Raghav]

Model and error looks like as shown in below image.

[R]

Hi Rajat,

This error is possibly occurring due to python caching your script in memory when it is first loaded. This means that python is executing the old version of the function which is cached in sys.modules. Follow the steps in this link to reload your module and see the new result in Simulink:

https://www.mathworks.com/help/matlab/matlab_external/call-user-defined-custom-module.html#buuz303:~:text=Jones%27%2C%20%27Johnson%27%2C%20%27James%27%5D-,Reload%20Modified%20User%2DDefined%20Python%20Module,-This%20example%20shows

[Abhishek]

Hi Bastin ,

I also have the same issue. I freshly loaded a python script into SIMULINK and it is causing the following error.

=== Simulation (Elapsed: 2 sec) ===

Error:MATLAB System block 'untitled/temp_generatesquarepulse' error occurred when invoking 'setupImpl' method of 'temp_generatesquarepulse'.

Caused by:

Invalid HandleObjectRef - Entry not found in the server table

The python code works well as standalone and it has Numpy also used. For the old function to be cached, this was loaded the first time without any memory. So not sure how it works.

[Abhishek]

Any idea why this error occurs ? I am still not able to solve this error for my simulink model when python code with numpy or other imports is imported using the python importer toolbox

[Bastiaan]

Sorry for the late reply, I was away for a while.

If I remeber correctly, the issue was that I hadn't installed python in the correct location. This meant that numpy wasnt installed in the correct location, so Matlab couldn't find the module. A coworker fixed it for me, so I am not 100% how to fix it exactly, but at least you now know a possible reason.

Another reason why this didn't work, was that the python file and generated matlab file have to be in the working directory. You can't generate a path to the python file (for some reason), so it has to be in the active folder.