Currently, only Gaussian kernels are implemented.
Original Python version by: Robert Kern
Date: 2004-08-09
Modified: 2005-02-10 by Robert Kern.
Contributed to Scipy
2005-10-07 by Robert Kern.
Some fixes to match the new scipy_core
Copyright 2004-2005 by Enthought, Inc.
Copyright 2003-2013 SciPy Developers.
All rights reserved.