Retrieve or set the dimension of an object.
dim(x)
dim(x) <- valuean R object, for example a matrix, array or data frame.
For the default method, either NULL or
a numeric vector, which is coerced to integer (by truncation).
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 replacement method changes the "dim" attribute (provided the
new value is compatible) and removes any "dimnames" and
"names" attributes.
The functions dim and dim<- are internal generic
primitive functions.
dim has a method for data.frames, which returns
the lengths of the row.names attribute of x and
of x (as the numbers of rows and columns respectively).
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
# NOT RUN {
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]
# }
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