array

R Base 3.6.2

Creates or tests for arrays.

Syntax

array(data = NA, dim = length(data), dimnames = NULL)
as.array(x, ...)
is.array(x)

Arguments

Parameter	Description
`data`	a vector (including a list or expression vector) giving data to fill the array. Non-atomic classed objects are coerced by as.vector.
`dim`	the dim attribute for the array to be created, that is an integer vector of length one or more giving the maximal indices in each dimension.
`dimnames`	either NULL or the names for the dimensions. This must a list (or it will be ignored) with one component for each dimension, either NULL or a character vector of the length given by dim for that dimension. The list can be named, and the list names will be used as names for the dimensions. If the list is shorter than the number of dimensions, it is extended by NULLs to the length required.
`x`	an R object.
`…`	additional arguments to be passed to or from methods.

Return Value

array returns an array with the extents specified in dim and naming information in dimnames. The values in data are taken to be those in the array with the leftmost subscript moving fastest. If there are too few elements in data to fill the array, then the elements in data are recycled. If data has length zero, NA of an appropriate type is used for atomic vectors (0 for raw vectors) and NULL for lists. Unlike matrix, array does not currently remove any attributes left by as.vector from a classed

Details

An array in R can have one, two or more dimensions. It is simply a vector which is stored with additional attributes giving the dimensions (attribute "dim") and optionally names for those dimensions (attribute "dimnames"). A two-dimensional array is the same thing as a matrix. One-dimensional arrays often look like vectors, but may be handled differently by some functions: str does distinguish them in recent versions of R. The "dim" attribute is an integer vector of length one or more containing non-negative values: the product of the values must match the length of the array. The "dimnames" attribute is optional: if present it is a list with one component for each dimension, either NULL or a character vector of the length given by the element of the "dim" attribute for that dimension. is.

Examples

Example

# NOT RUN {
dim(as.array(letters))
array(1:3, c(2,4)) # recycle 1:3 "2 2/3 times"
#     [,1] [,2] [,3] [,4]
#[1,]    1    3    2    1
#[2,]    2    1    3    2
# }