kronecker

R Base 3.6.2

Computes the generalised kronecker product of two arrays, X and Y.

Syntax

kronecker(X, Y, FUN = "*", make.dimnames = FALSE, &#8230;)
X %x% Y

Arguments

Parameter	Description
`X`	A vector or array.
`Y`	A vector or array.
`FUN`	a function; it may be a quoted string.
`make.dimnames`	Provide dimnames that are the product of the dimnames of X and Y.
`…`	optional arguments to be passed to FUN.

Return Value

An array A with dimensions dim(X) * dim(Y).

Details

If X and Y do not have the same number of dimensions, the smaller array is padded with dimensions of size one. The returned array comprises submatrices constructed by taking X one term at a time and expanding that term as FUN(x, Y, ...). %x% is an alias for kronecker (where FUN is hardwired to "*").

Examples

Example

# NOT RUN {
# simple scalar multiplication
( M <- matrix(1:6, ncol = 2) )
kronecker(4, M)
# Block diagonal matrix:
kronecker(diag(1, 3), M)

# ask for dimnames

fred <- matrix(1:12, 3, 4, dimnames = list(LETTERS[1:3], LETTERS[4:7]))
bill <- c("happy" = 100, "sad" = 1000)
kronecker(fred, bill, make.dimnames = TRUE)

bill <- outer(bill, c("cat" = 3, "dog" = 4))
kronecker(fred, bill, make.dimnames = TRUE)
# }