* Matrix-vector multiplication. A is a matrix or spmatrix of size (m, n) where N = dims['l'] + sum(dims['q']) + sum( k**2 for k in dims['s'] ) representing a mapping from R^n to S. If trans is 'N': y := alpha*A*x + beta * y (trans = 'N'). x is a vector of length
(A, x, y *matrix.FloatMatrix, alpha, beta float64, dims *sets.DimensionSet, opts ...la_.Option)