dim {base} | R Documentation |
Retrieve or set the dimension of an object.
dim(x) dim(x) <- value
x |
an R object, for example a matrix, array or data frame. |
value |
For the default method, either NULL or
a numeric vector which coerced to integer (by truncation). |
The functions dim
and dim<-
are generic.
dim
has a method for data.frame
s, which returns
the length of the row.names
attribute of x
and the
length of x
(the numbers of “rows” and “columns”).
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
.
The replacemnt method changes the "dim"
attribute (provided the
new value is compatible) and removes any "dimnames"
and
"names"
attributes.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
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]