I am writing a program which operate solely on matrices of size that is constant, that is, determined at the compile time. I am trying to write a subroutine that computes the column-wise Kronecker product, aka Khatris-Rao product, for the program.

The subroutine will have as input matrices of constant size, outputs a matrix of size dependent on the input, but still constant. It will have a loop for a number of times dependent on the input, but again, still determined at compile time. I might want to allocate a matrix of size dependent on the input, but, again, still constant.

What is the right way of writing such a function, with the optimization for temporaries and constant-sized matrices working?

Why not using the unsupported module for Kronecker products:

http://eigen.tuxfamily.org/dox-devel/un ... odule.html

ggael wrote:Why not using the unsupported module for Kronecker products:

http://eigen.tuxfamily.org/dox-devel/un ... odule.html

Yes, of course I could, but I'm trying to learn how to write functions that uses the infrastructure offered by Eigen.