Multiply the rows or columns of a matrix by the elements of a vector.
Usage
matvec(M, v)
vecmat(v, M)
Arguments
M
numeric matrix, or object which can be coerced to a matrix.
v
numeric vector, or object which can be coerced to a vector. Length should match the number of columns of M (for matvec) or the number of rows of M (for vecmat)
Details
matvec(M,v) is equivalent to M %*% diag(v) but is faster to execute.
Similarly vecmat(v,M) is equivalent to diag(v) %*% M but is faster to execute.
Value
A matrix of the same dimensions as M.
Author(s)
Gordon Smyth
Examples
A <- matrix(1:12,3,4)
A
matvec(A,c(1,2,3,4))
vecmat(c(1,2,3),A)