| make.unique {base} | R Documentation |
Make Character Strings Unique
Description
Makes the elements of a character vector unique by appending sequence numbers to duplicates.
Usage
make.unique(names, sep = ".")
Arguments
names |
a character vector |
sep |
a character string used to separate a duplicate name from its sequence number. |
Details
The algorithm used by make.unique has the property that
make.unique(c(A, B)) == make.unique(c(make.unique(A), B)).
In other words, you can append one string at a time to a vector,
making it unique each time, and get the same result as applying
make.unique to all of the strings at once.
If character vector A is already unique, then
make.unique(c(A, B)) preserves A.
Value
A character vector of same length as names with duplicates changed.
Author(s)
Thomas P Minka
See Also
make.names
Examples
make.unique(c("a", "a", "a"))
make.unique(c(make.unique(c("a", "a")), "a"))
make.unique(c("a", "a", "a.2", "a"))
make.unique(c(make.unique(c("a", "a")), "a.2", "a"))
rbind(data.frame(x=1), data.frame(x=2), data.frame(x=3))
rbind(rbind(data.frame(x=1), data.frame(x=2)), data.frame(x=3))