R: Dimensions of an Object (original) (raw)
| dim {base} | R Documentation |
|---|
Description
Retrieve or set the dimension of an object.
Usage
dim(x)
dim(x) <- value
Arguments
| x | an R object, for example a matrix, array or data frame. |
|---|---|
| value | for the default method, either NULL or a numeric vector, which is coerced to integer (by truncation). |
Details
The functions dim and dim<- are internal generic primitive functions.
dim has a method for [data.frame](../../base/help/data.frame.html)s, which returns the lengths of the row.names attribute of x and of x (as the numbers of rows and columns respectively).
Value
For an array (and hence in particular, for a matrix) dim retrieves the dim attribute of the object. It is NULL or a vector of mode [integer](../../base/help/integer.html).
The replacement method changes the "dim" attribute (provided the new value is compatible) and removes any "dimnames" and "names" attributes.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)The New S Language. Wadsworth & Brooks/Cole.
See Also
[ncol](../../base/help/ncol.html), [nrow](../../base/help/nrow.html) and [dimnames](../../base/help/dimnames.html).
Examples
x <- 1:12 ; dim(x) <- c(3,4)
x
# simple versions of nrow and ncol could be defined as follows
nrow0 <- function(x) dim(x)[1]
ncol0 <- function(x) dim(x)[2]
[Package _base_ version 4.6.0 Index]