R: inner product for matrices and vectors

matmult {compositions} | R Documentation

## 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 `%*%` 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

[Package compositions version 1.40-5 Index]