Functions to get or set the names of an object.
names(x) names(x) <- value
- an R object.
- a character vector of up to the same length as
names is a generic accessor function, and
names<- is a generic replacement function. The default methods get and set the
"names" attribute of a vector (including a list) or pairlist.
value is shorter than
x, it is extended by character
NAs to the length of
It is possible to update just part of the names attribute via the general rules: see the examples. This works because the expression there is evaluated as
z <- "names<-"(z, "[<-"(names(z), 3, "c2")).
"" is special: it is used to indicate that there is no name associated with an element of a (atomic or generic) vector. Subscripting by
"" will match nothing (not even elements which have no name).
A name can be character
NA, but such a name will never be matched and is likely to lead to confusion.
Both are primitive functions.
NULL or a character vector of the same length as
NULL is given if the object has no names, including for objects of types which cannot have names.)
names<-, the updated object. (Note that the value of
names(x) <- value is that of the assignment,
value, not the return value from the left-hand side.)
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
For vectors, the names are one of the attributes with restrictions on the possible values. For pairlists, the names are the tags and converted to and from a character vector.
# print the names attribute of the islands data set names(islands) # remove the names attribute names(islands) <- NULL islands rm(islands) # remove the copy made z <- list(a = 1, b = "c", c = 1:3) names(z) # change just the name of the third element. names(z) <- "c2" z z <- 1:3 names(z) ## assign just one name names(z) <- "b" z
Documentation reproduced from R 3.0.2. License: GPL-2.