Retrieve or set the row or column names of a matrix-like object.
rownames(x, do.NULL = TRUE, prefix = "row") rownames(x) <- value colnames(x, do.NULL = TRUE, prefix = "col") colnames(x) <- value
- a matrix-like R object, with at least two dimensions for
- logical. Should this create names if they are
- for created names.
- a valid value for that component of
dimnames(x). For a matrix or array this is either
NULLor a character vector of non-zero length equal to the appropriate dimension.
The extractor functions try to do something sensible for any matrix-like object
x. If the object has
dimnames the first component is used as the row names, and the second component (if any) is used for the column names. For a data frame,
colnames eventually call
names respectively, but the latter are preferred.
FALSE, a character vector (of length
NCOL(x)) is returned in any case, prepending
prefix to simple numbers, if there are no dimnames or the corresponding component of the dimnames is
The replacement methods for arrays/matrices coerce vector and factor values of
value to character, but do not dispatch methods for
For a data frame,
rownames should be a character vector of non-duplicated and non-missing names (this is enforced), and for
colnames a character vector of (preferably) unique syntactically-valid names. In both cases,
value will be coerced by
as.character, and setting
colnames will convert the row names to character.
Documentation reproduced from R 2.13.1. License: GPL-2.