hyperSpec (version 0.95)

array2vec: Converting array and vector Indices

Description

Calculate the vector index from array indices, and vice versa.

Usage

array2vec(iarr, dim)
vec2array(ivec, dim)

Arguments

iarr

vector with the indices into the array dimensions

ivec

scalar with the index into the vector

dim

vector with the array dimensions, as returned by dim (x)

Value

• array2vec returns a scalar, vec2array a matrix.

Details

arrays are numerics with a dim attribute and are stored with the first index moving fastest (i.e. by column). They can be indexed both ways.

See Also

see Extract on the difference of indexing an array with a vector or a matrix.

Examples

arr <- array (rnorm (24), dim = 2 : 4)
arr

v <- matrix(c(2, 2, 2), nrow = 1)
i <- array2vec (v, dim = dim (arr))
i
arr[v]
arr[i]

arr[c(2, 2, 2)] ## indexing with a vector
arr[2]

i <- 14
v <- vec2array (i, dim = dim (arr))
v
arr [v]
arr [i]