What is the correct way of Plotting Matlab's .mat -data in Sage?

[Sami]

What is the right way of importing Matlab's .mat data into SageMath?

Or to which format should I transform this data for Sage notebook?

Possibly, there is some restrictions in the Notebook, which can be a reason why the data is not plotting.

I am considering the problem also here: http://superuser.com/questions/687891/to-plot-matlab-data-in-sagemath

[kcrisman]

See my answer there - basically, you have to first import the .mat file, then you have to turn it from (e.g.) Numpy into Sage.

To the experts: however, I noticed some things while doing this. 

import numpy

L = numpy.array([[1.0,2.0]])

matrix(L)

works, but 

import numpy

L = numpy.array([1.0,2.0])

matrix(L)

Okay, I get why, but maybe we should at least have a better error message?  Or can we assume that such arrays *should* be convertible to matrices?