# dim {base}

### 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`

s, which returns the lengths of the `row.names`

attribute of `x`

and of `x`

(as the numbers of rows and columns respectively).

### Values

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.

### References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) *The New S Language*. Wadsworth & Brooks/Cole.

### Examples

Documentation reproduced from R 3.0.2. License: GPL-2.