Implement subset of linear algebra

[wadetb]

http://docs.scipy.org/doc/numpy/reference/routines.linalg.html

Need to identify most useful routines.

[EpicWink]

I use the following methods in my codebase:

• numpy.linalg.det
• numpy.linalg.eig
• numpy.linalg.inv
• numpy.linalg.LinAlgError
• numpy.linalg.lstsq
• numpy.linalg.norm
• numpy.linalg.svd

Of these, I use norm all the time, and I only use svd and lstsq once.

Also numpy.einsum is a general routine which can be used for many operations in linear algebra.