mcmcsae (version 0.6.0)

matrix-vector: Fast matrix-vector multiplications

Description

Functions for matrix-vector multiplies like %*% and crossprod, but often faster for the matrix types supported. The return value is always a numeric vector.

Usage

M %m*v% v
crossprod_mv(M, v)

Arguments

M

a matrix of class 'matrix', 'dgCMatrix', 'dsCMatrix', 'tabMatrix', or 'ddiMatrix'.

v

a numeric vector.

Value

For %m*v% the vector $Mv$ and for crossprod_mv the vector $M^{\prime }v$ where $M^{\prime }$ denotes the transpose of $M$.

Examples

# NOT RUN {
M <- matrix(rnorm(10*10), 10, 10)
x <- rnorm(10)
M %m*v% x
crossprod_mv(M, x)
M <- Matrix::rsparsematrix(100, 100, nnz=100)
x <- rnorm(100)
M %m*v% x
crossprod_mv(M, x)

# }