array
Multi-Way Arrays
Description
Creates or tests for an array. Arrays are matrices and
higher-dimensional generalizations of matrices.
Usage
array(data = NA, dim = length(data), dimnames = NULL)
is.array(x)
as.array(x, ...)
## Default S3 method:
as.array(x, ...)
Arguments
| data |
a vector containing the data values for the array in
the normal array order: the first subscript varies most
rapidly and the last subscript varies least rapidly.
Missing values (NAs) are allowed.
|
| dim |
a vector giving the extent for each dimension. The dim
attribute of the array.
|
| dimnames |
a list giving the dimnames for the array.
This must satisfy certain criteria. See the DETAILS section for
more information.
|
| x |
a vector.
|
| ... |
reserved arguments for future use.
|
Details
The array class of objects are those that have an attribute dim, which is
a vector of integers whose product equals the length of data.
An array can also have an attribute dimnames. This is a list of length(dim)
components, each of which is either of length zero, or a vector of character strings that
gives the labels corresponding to the levels of the corresponding subscript in the array.
Thus, length(dimnames(x)[[i]]) must equal either 0 or dim(x)[i].
as.array is generic. Only the default method is implemented at present.
Value
| array | returns an array with the same mode as data, the dimensionality
described by dim, and the optional dimnames attribute. If data is too short to fill
the specified array, the data is repeated until the array is filled. If data is too long to fit into
the specified array, the data is truncated. |
| is.array | returns TRUE if x is an array object (has a dim attribute);
otherwise it returns FALSE. |
| as.array.default | returns x, if x is an array; otherwise it returns a 1-dimensional
array with data from x and a dim attribute equal to length(x). |
See Also
Examples
# creates a 2 by 4 by 3 array
newarray <- array(c(1:8, 11:18, 111:118), dim = c(2,4,3),
dimnames = list(c("r1", "r2"), NULL, c("c1", "c2", "c3")) )
is.array(newarray)
# [1] TRUE
as.array(newarray)
x <- runif(12)
names(x) <- as.character(1:12)
as.array.default(x)