Deane Yang <deane_yang@yahoo.com> writes:
Michael Stevens wrote:
This is very odd. In linear algebra there is no such thing as a matrix of matrices.
Yes, there is. It's a linear transformation mapping a space of matrices to another space of matrices.
But could Jeremy or David provide some examples of useful applications of such an object? They are immensely useful in pure mathematics; I would love to know how they arise in more practical areas.
They're used in numerical simulations in the frequency domain (http://www.cercom.polito.it/Publication/Pdf/28.pdf), and they form the basis for the validity of many blocked matrix operations. The fact that you can view it as an optimization or an operation on a matrix of matrices should mean that you can achieve better code reuse in the library. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com