abbreviate {base}R Documentation

Abbreviate Strings

Description

Abbreviate strings to at least minlength characters, such that they remain unique (if they were).

Usage

abbreviate(names.arg, minlength = 4, use.classes = TRUE,
           dot = FALSE)

Arguments

names.arg a vector of names to be abbreviated.
minlength the minimum length of the abbreviations.
use.classes logical (currently ignored by R).
dot logical; should a dot (".") be appended?

Details

The algorithm used is similar to that of S. First spaces at the beginning of the word are stripped. Then any other spaces are stripped. Next lower case vowels are removed followed by lower case consonants. Finally if the abbreviation is still longer than minlength upper case letters are stripped.

Letters are always stripped from the end of the word first. If an element of names.arg contains more than one word (words are separated by space) then at least one letter from each word will be retained. If a single string is passed it is abbreviated in the same manner as a vector of strings.

Missing (NA) values are not abbreviated.

If use.classes is FALSE then the only distinction is to be between letters and space. This has NOT been implemented.

Value

A character vector containing abbreviations for the strings in its first argument. Duplicates in the original names.arg will be given identical abbreviations. If any non-duplicated elements have the same minlength abbreviations then minlength is incremented by one and new abbreviations are found for those elements only. This process is repeated until all unique elements of names.arg have unique abbreviations.
The character version of names.arg is attached to the returned value as a names argument.

Warning

This is really only suitable for English, and does not work correctly with non-ASCII characters in UTF-8 locales. It will warns if used with non-ASCII characters.

See Also

substr.

Examples

x <- c("abcd", "efgh", "abce")
abbreviate(x, 2)

(st.abb <- abbreviate(state.name, 2))
table(nchar(st.abb))# out of 50, 3 need 4 letters

[Package base version 2.1.0 Index]