Matlab Runtime "Error on flush"

I am trying to use Python and MATLAB Runtime to call some code that was previously compiled using the MATLAB compiler. It's giving me the following error:

MatlabRuntimeError: An error occurred when evaluating the result from a function. Details: Error on flush.

Googling the error didn't turn anything up. Does anyone know what this might mean? I have double-checked that I am using the correct version of the compiler (9.4 R2018a), and I get the same error message whether I'm using Python 2.7 or 3.6. The MATLAB code works fine when run from MATLAB proper.

Any help would be very much appreciated!

Answer 1

[Olli Tanskanen]

I encountered the issue as well.

I was able to reproduce the issue reliably when using pyinstaller with console option set to false (when false it won't show a console window, only your applicaton window), but when I ran the pyinstaller with console option set to true everything worked just fine. The bug seems to be related to stdout not 'existing' which causes issues in matlab side.

I was able to fix the problem with any of these:

1. Redirecting stdout and stderr to StringIO stream (see example below)
2. Having a console window visible
3. Removing all disp functions from matlab code

Example on how to redirect stdout:

import io

import your_matlab_package

p_handle = your_matlab_package.initialize()
p_handle.your_matlab_function(..., stdout=io.StringIO(), stderr=io.StringIO())

If you want to actually show matlab disp results in python side you can of couse create a new class which inherits StringIO and override the write function where you would actually show/log the matlab output.

[W Grootjans]

Thanks for this response. This fixed my problem for this very niche use case. Very much appreciated!!!

Answer 2

[Andreas Blassnig]

Could you find a solution for this Problem? (I got the same error message.)

Best regards

[KB]

Hi Andreas,

Afraid not- I haven't been able to find any more information. Maybe now that there's two of us it will help with the question's visibility, though.

Answer 3

[kok wei]

I'm facing this issue with MATLAB R2019a and Python 3.6.8 as well. Appreciate for any further inputs.

Answer 4

[yusuf elezler]

The problem is display functions like disp('xxxx'). Delete or comment it and compile again. It'll work.