make.names {base} | R Documentation |
Make syntactically valid names out of character vectors.
make.names(names, unique = FALSE)
names |
character vector to be coerced to syntactically valid names. This is coerced to character if necessary. |
unique |
logical; if TRUE , the resulting elements are
unique. This may be desired for, e.g., column names. |
A syntactically valid name consists of letters, numbers, and the dot
character and starts with a letter or the dot. Names such as
".2"
are not valid, and neither are the reserved words.
The character "X"
is prepended if necessary.
All invalid characters are translated to "."
. A missing value
is translated to "NA"
. Names which match R keywords have a dot
appended to them. Duplicated values are altered by
make.unique
.
A character vector of same length as names
with each changed to
a syntactically valid name.
make.unique
,
names
,
character
,
data.frame
.
make.names(c("a and b", "a_and_b"), unique=TRUE) # "a.and.b" "a.and.b.1" data(state) state.name[make.names(state.name) != state.name] # those 10 with a space