agrep {base}  R Documentation 
Searches for approximate matches to pattern
(the first argument)
within the string x
(the second argument) using the Levenshtein
edit distance.
agrep(pattern, x, ignore.case = FALSE, value = FALSE, max.distance = 0.1)
pattern 
a nonempty character string to be matched (not
a regular expression!). Coerced by as.character to a string
if possible. 
x 
character vector where matches are sought. Coerced by
as.character to a character vector if possible. 
ignore.case 
if FALSE , the pattern matching is case
sensitive and if TRUE , case is ignored during matching. 
value 
if FALSE , a vector containing the (integer)
indices of the matches determined is returned and if TRUE , a
vector containing the matching elements themselves is returned. 
max.distance 
Maximum distance allowed for a match. Expressed
either as integer, or as a fraction of the pattern length (will be
replaced by the smallest integer not less than the corresponding
fraction), or a list with possible components
all is missing, it is set to 10%, the other components
default to all . The component names can be abbreviated.

The Levenshtein edit distance is used as measure of approximateness: it is the total number of insertions, deletions and substitutions required to transform one string into another.
The function is a simple interface to the apse
library
developed by Jarkko Hietaniemi (also used in the Perl String::Approx
module).
Either a vector giving the indices of the elements that yielded a
match, of, if value
is TRUE
, the matched elements (after
coercion, preserving names but no other attributes).
David Meyer David.Meyer@wuwien.ac.at (based on C code by Jarkko Hietaniemi); modifications by Kurt Hornik.
agrep("lasy", "1 lazy 2") agrep("lasy", "1 lazy 2", max = list(sub = 0)) agrep("laysy", c("1 lazy", "1", "1 LAZY"), max = 2) agrep("laysy", c("1 lazy", "1", "1 LAZY"), max = 2, value = TRUE) agrep("laysy", c("1 lazy", "1", "1 LAZY"), max = 2, ignore.case = TRUE)