4

I am translating code from matlab to python. I am using matlab engine provided by mathworks to partially call chunks of the old matlab code in the midst of what it has already been translated to python.

For example:

//python already translated code 
x = matlabEngineObject.matlab_function_example_1(arg1)
//more python already translated code using x
y = matlabEnginObject.matlab_function_example_2(x)
//more python

Following my code example, my problem is that in Windows I cannot pass x as argument to the second matlab function if it is an instance of matlab.double, which makes no sense because I think that is the main goal of that data type.

However, in Linux Ubuntu I can do it without trouble. I generally work in Linux Ubuntu but I need the code to run in Windows too.

The error I get trying to pass a matlab.double to a matlab function through a matlab engine is the one below 

>>> b  = eng.test2(matlab.double([1,2]))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Users\Tomas 
Pastore\AppData\Local\Programs\Python\Python35\lib\site- 
packages\matlab\engine\matlabengine.py", line 79, in __call__
out=_stdout, err=_stderr)
TypeError: unsupported Python data type: matlab.double

I checked python versions between the two systems -> both 3.5.2 I have also checked matlab versions, they are both R2017a, the only difference is the arch because of the OS I guess (linux is glnxa64 and windows is win64).

The only difference I found between both environments is that printing this object class name, in linux I get mlarray.double instead of matlab.double in windows. However, in both systems this data type is returned by the same constructor, ej: matlab.double([1,2]).

Data type of matlab.double in Linux ubuntu (working) Data type of matlab.double in Linux ubuntu (working)

Data type of matlab.double in Windows (not working) Data type of matlab.double in Windows (not working)

Last, I can say that other features of the engine are working correctly in windows as I tested other functions and they work fine.

My doubts are:
1) Why does the same version of python output a different type for the same object.
2) How can I get matlab.double get accepted by matlab engine in windows.

Thanks in advance

Nic3500
  • 8,144
  • 10
  • 29
  • 40
tpastore
  • 41
  • 1
  • In your screen capture from Ubuntu, you put `import matlab engine` **no dot**. In Windows, you put `import matlab.engine` **with dot**. Put a dot in Ubuntu as well. – Nic3500 Oct 13 '18 at 01:08
  • that was because of quick tipying, if you see the next line of ubuntu, I wrote the correct import there, that has nothing to do with this unluckily. Thanks though – tpastore Oct 13 '18 at 02:56

0 Answers0