Names Attribute of an Object

DESCRIPTION:

Returns or changes the names attribute of an object, usually a list or a vector.

USAGE:

names(x) 
names(x) <- value 

REQUIRED ARGUMENTS:

x
any object.

OPTIONAL ARGUMENTS:

value
vector of character strings. This must have the same length as x.

VALUE:

if x has a names attribute, this attribute is returned; otherwise, it returns NULL. The names attribute can be used for subset and element selection. It is a character vector the same length as x.

SIDE EFFECTS:

On the left side of an assignment, the names attribute of x is set to value, which must have the same length as x. To explicitly delete the names attribute, use names(x) <- NULL.

A names attribute cannot be added to a matrix or array, as these structures store names in a dimnames attribute. If x is a matrix with a single column, then value is used as the row names. If x is an array with a single dimension, value is used as the names of the first dimension. Otherwise, the assignment stops with an error when x is a matrix or array.

You should not remove names from a data frame; this would create an illegal data frame, and some operations will fail.

DETAILS:

Use "" in value for the objects in x that do not have names.

A bdVector does not contain names, so names(x) always returns NULL, and names(x) <- value does nothing.

The value may be a character vector, or anything that can be coerced to a character vector. However, it should not be a bdCharacter or other bdVector; you can convert these to an ordinary vector using bd.coerce

Instead of using names to replace row names from a matrix, use rowIds or dimnames.

NOTE:

See as.name for objects of mode "name".

SEE ALSO:

, , , , , (and rownames), .

EXAMPLES:

x.name <- x[names(x)!=""] 
        # find the elements of x with non-null names 
ozone.xy[["x"]] # alternative to ozone.xy$x