>>> from scipy.io import savemat
>>> a = np.arange(20)
>>> mdic = {"a": a, "label": "experiment"}
>>> mdic
{'a': array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16,
    17, 18, 19]),
'label': 'experiment'}
>>> savemat("matlab_matrix.mat", mdic)