aplus {magic}

Generalized array addition

Description

Given two arrays a and b with length(dim(a))==length(dim(b)), return a matrix with dimensions pmax(dim(a),dim(b)) where “overlap” elements are a+b, and the other elements are either 0, a, or b according to location. See details section.

Usage

aplus(...)

Arguments

...

numeric or complex arrays

Details

The function takes any number of arguments (the binary operation is associative).

The operation of aplus() is understandable by examining the following pseudocode:

• outa <- array(0,pmax(a,b))

• outb <- array(0,pmax(a,b))

• outa[1:dim(a)] <- a

• outb[1:dim(a)] <- b

• return(outa+outb)

See how outa and outb are the correct size and the appropriate elements of each are populated with a and b respectively. Then the sum is returned.

Author(s)

Robin K. S. Hankin

See Also

apad

Examples

aplus(rbind(1:9),cbind(1:9))

a <- matrix(1:8,2,4)
b <- matrix(1:10,5,2)
aplus(a*100,b,b)