make.names               package:base               R Documentation

Make Syntactically Valid Names

Description:

     Make syntactically valid names out of character vectors.

Usage:

     make.names(names, unique = FALSE)

Arguments:

   names: character (vector) to be coerced to syntactically valid
          names.

  unique: logical; if `TRUE', the resulting elements are unique.  This
          may be desired for, e.g., column names.

Details:

     A syntactically valid name consists of letters, numbers, and the
     dot character and starts with a letter or the dot.

     All invalid characters are translated to `"."'.

Value:

     A character vector of same length as `names' with each changed to
     a syntactically valid name.

See Also:

     `names', `character', `data.frame'.

Examples:

     make.names(c("a and b", "a_and_b"), unique=TRUE)#-> "a.and.b"  "a.and.b1"

     all(make.names(letters) == letters)# TRUE

     data(state)
     state.name[make.names(state.name) != state.name]# those 10 with a space

