This is a wrapper around general dense or sparse dot products.
It is not necessary except as a common interface for supporting ndarray, scipy spmatrix, and PySparse arrays.
Returns the inner product of the (m x n) dense or sparse matrix A with the n-element dense array v. This is a wrapper for A.dot(v) for dense arrays and spmatrix objects, and for A.matvec(v, result) for PySparse matrices.