dimnames {base}R Documentation

Dimnames of an Object

Description

Retrieve or set the dimnames of an object.

Usage

dimnames(x)
dimnames(x) <- value

Arguments

x an R object, for example a matrix, array or data frame.
value a possible value for dimnames(x): see “Value”.

Details

The functions dimnames and dimnames<- are generic.

For an array (and hence in particular, for a matrix), they retrieve or set the dimnames attribute (see attributes) of the object. A list value can have names, and these will be used to label the dimensions of the array where appropriate.

For an array/matrix, vector and factor components of value will be coerced to character, but no other coercions are done.

Both have methods for data frames. The dimnames of a data frame are its row.names and its names. For the replacement method each component of value will be coerced by as.character.

Value

The dimnames of a matrix or array can be NULL or a list of the same length as dim(x). If a list, its components are either NULL or a character vector the length of the appropriate dimension of x.
For the "data.frame" method both dimnames must be non-null, and the rownames must be contain no duplicates nor missing values.

References

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

See Also

rownames, colnames; array, matrix, data.frame.

Examples

## simple versions of rownames and colnames
## could be defined as follows
rownames0 <- function(x) dimnames(x)[[1]]
colnames0 <- function(x) dimnames(x)[[2]]

[Package base version 2.3.0 Index]