dim attribute, which describes the dimensions of
a matrix, data frame,
bdFrame, or array.
dim(x) dim(x) <- value
x(missing values are not
allowed), or
NULL.
x, if any; and
NULL if
x does
not have dimensions.
dim(x) establishes or changes the
dim
attribute of
x if it is an array or matrix;
no re-ordering of the elements of
x is implied.
If the object had
names
(a
"names" attribute) they are currently deleted.
This is a generic function,
dim has a method for data frames and
bdFrames, which
counts the length of the
row.names attribute and the number of columns.
You may not change the dimensions of a data frame or
bdFrame.
Arrays and matrices have a
dim attribute which is an integer vector,
with the property that
prod(dim(x))==length (x).
This attribute identifies an object as an array.
dim(iris) # returns c(50, 4, 3)
length(dim(y)) # number of dimensions of y
if(!is.null(dim(z))) { .. z .. } # do not operate on non-array data
if(is.array(z)) { .. z .. } # better way to do the same thing