# Ttclass/hdot.m

From Spinach Documentation Wiki

Hadamard matrix product. Useful as a replacement for trace(A'*B) because trace(A'*B)=hadm(conj(A),B) and the latter only needs O(n^2) multiplications as opposed to O(n^3) for trace(A'*B). Syntax:

H=hdot(A,B)

This function is also available for tensor train representations of matrices.