Extract Part of a String
Extract a part of a string, defined as regular expression. StrExtractBetween() is a convenience function used to extract parts between a left and right delimiter.
StrExtract(x, pattern, ...) StrExtractBetween(x, left, right, greedy = FALSE)
x |
a character vector where matches are sought, or an object which can be coerced by |
pattern |
character string containing a regular expression (or character string for |
left |
left character(s) limiting the string to be extracted |
right |
right character(s) limiting the string to be extracted |
greedy |
logical, determines whether the first found match for |
... |
the dots are passed to the the internally used function |
The function wraps regexpr and regmatches.
A character vector.
Andri Signorell <andri@signorell.net>
txt <- c("G1:E001", "No points here", "G2:E002", "G3:E003", NA)
# extract everything after the :
StrExtract(x=txt, pattern=":.*")
# extract everything between "left" and "right"
z <- c("yBS (23A) 890", "l 89Z) 890.?/", "WS (55X) 8(90)", "123 abc", "none", NA)
# everything enclosed by spaces
StrExtractBetween(z, " ", " ")
# note to escape special characters
StrExtractBetween(z, "\\(", "\\)")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.