note:
the KronProd kronecker product class by Matt Jacobson
may be useful for refining some of these operations.

http://www.mathworks.com/matlabcentral/fileexchange/25969-efficient-object-oriented-kronecker-product-manipulation


For T0 = BsplCo2Val and T0inv = BsplVal2Co,
we sometimes need the adjoint (transpose)
which can be evaluated as follows (2010-04-13 email from Se Young Chun)
T0inv' = inv(T0') = inv(T0) = T0inv (because T0 = T0')


Caution: T0 * T0inv is not always the identity matrix
when using the BsplVal2CoMirr / BsplCo2ValMirr pair,
as found by Jan Hwan Cho circa 2011-11 so Se Young Chun
recommends using BsplVal2CoZero instead.