PendingDeprecationWarning: the matrix subclass is not the recommended way to represent matrices

[bollard]

Hi all,

Just started using your package (v1.4.0) and note the following warnings popping up from Numpy:

PendingDeprecationWarning: the matrix subclass is not the recommended way to represent matrices or deal with linear algebra (see https://docs.scipy.org/doc/numpy/user/numpy-for-matlab-users.html). Please adjust your code to use regular ndarray.

One place for example is the call to np.asmatrix here, but sure there are more.

Thanks