matmult {compositions}

inner product for matrices and vectors

Description

Multiplies two matrices, if they are conformable. If one argument is a vector, it will be coerced to either a row or a column matrix to make the two arguments conformable. If both are vectors it will return the inner product.

Usage

x %*% y
## Default S3 method:
x %*% y

Arguments

x, y

numeric or complex matrices or vectors

Details

This is a copy of the base::%*% function. The function is made generic to allow the definition of specific methods.

Value

The matrix product. Uses 'drop' to get rid of dimensions which have only one level.

Author(s)

K.Gerald v.d. Boogaart http://www.stat.boogaart.de

See Also

%*%.rmult

Examples

M <- matrix(c(
0.2,0.1,0.0,
0.1,0.2,0.0,
0.0,0.0,0.2),byrow=TRUE,nrow=3)
x <- c(1,1,2)
M %*% x
x %*% M
x %*% x
M %*% M
t(x) %*% M