Approximate String Match Positions
Determine positions of approximate string matches.
aregexec(pattern, text, max.distance = 0.1, costs = NULL, ignore.case = FALSE, fixed = FALSE, useBytes = FALSE)
- a non-empty character string or a character string
containing a regular expression (for
fixed = FALSE) to be matched. Coerced by
as.characterto a string if possible.
- character vector where matches are sought.
as.characterto a character vector if possible.
- maximum distance allowed for a match.
- cost of transformations.
- a logical. If
TRUE, case is ignored for computing the distances.
TRUE, the pattern is matched literally (as is). Otherwise (default), it is matched as a regular expression.
- a logical. If
TRUEcomparisons are byte-by-byte rather than character-by-character.
aregexec provides a different interface to approximate string
agrep (along the lines of the interfaces
to exact string matching provided by
grep). Note that by default,
agrep performs literal matches,
aregexec performs regular expression matches. See
adist for more information
about approximate string matching and distances. Comparisons are byte-by-byte if
pattern or any element of
text is marked as
A list of the same length as
text, each element of which is
either \(-1\) if there is no match, or a sequence of integers with
the starting positions of the match and all substrings corresponding
to parenthesized subexpressions of
pattern, with attribute
"match.length" an integer vector giving the lengths of the
matches (or \(-1\) for no match).
regmatches for extracting the matched substrings.
## Cf. the examples for agrep. x <- c("1 lazy", "1", "1 LAZY") aregexec("laysy", x, max.distance = 2) aregexec("(lay)(sy)", x, max.distance = 2) aregexec("(lay)(sy)", x, max.distance = 2, ignore.case = TRUE) m <- aregexec("(lay)(sy)", x, max.distance = 2) regmatches(x, m)