def innerproduct$($X$,$Z$=$None$)$:

# function innerproduct$($X$,$Z$)$

#

# Computes the inner$-$product matrix.

# Syntax:

# D$=$innerproduct$($X$,$Z$)$

# Input:

# X: nxd data matrix with n vectors $($rows$)$ of dimensionality d

# Z: mxd data matrix with m v