Can you use .toarray() for to transform matlab.double objects to python arrays?

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I have to transform N, a matlab.double object, size 118x4, to an python array in the fastest way possible, can you use the .toarray() function?
Otherwise I am doing numpy.asarray(N._data) which is fast, but not the best option.

Answers (1)

Kunal Kandhari
Kunal Kandhari on 7 Dec 2022
There are a couple of ways to accomplish this. One method is to use numpy's built-in method, 'asarray':
Start by loading your matlab.double array:
myData = eng.eval("load('{}','cluster_class','par')".format('sampleData.mat'))
With MATLAB R2022a and later, you can convert matlab.double directly to a numpy array:
a = np.array(myData['cluster_class'])
To add additional specification, use MATLAB engine's functions to convert to a Python array with 'noncomplex()', then to a numpy array:
a = np.array(myData['cluster_class'].noncomplex().toarray(), 'int')
We use the 'noncomplex()' call to retrieve the data in 1D format (provided it's noncomplex; for complex data, we can use 'real()' and 'imag()' calls). We also offer the 'toarray()' call to convert a 1D matlab.double into a Python array.array object.
  1 Comment
Anna Varbella
Anna Varbella on 7 Dec 2022
Thank you for you answer! However I'm not trying to load a saved .mat file, but I already get my data in python as a matlab double, saving and loading would slow down a lot my program.

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