Description Usage Arguments Details Value Examples
Pulls out the matches for marked regions of regular expressions.
1 | extractMatches(data, pattern, var, ...)
|
data |
a data frame. Or, use a pipe to specify the data frame. |
pattern |
the regex to be used for matching |
var |
the name of the variable from which to extract the substrings |
... |
reserved for future use |
Wrap regexes in parentheses to signal that the matching content is to be extracted as a string.
Use parentheses to mark out parts of regular expressions
that identify substrings to be extracted if there is a match.
For instance, the pattern "(.*)[aeiouy]$"
matches all strings ending in a vowel.
The "(.*)"
indicates that the substring to be extracted is all the characters in
the string up to that final vowel. NA is returned for strings that have no match.
a data frame that copies the original but adds a new variable giving the substring identified in the first parentheses. If there are more than one set of extraction parentheses, a new variable is added for each.
1 2 3 4 5 6 | # grab the root of names ending in vowels.
BabyNames %>% head %>% extractMatches(pattern="(.*)[aeiouy]$", name)
# Two matches:
# grab the first letter (if capitalized) in strings ending in a vowel
# also grab any letter between the third character and an ending vowel.
BabyNames %>% head %>% extractMatches(pattern="^([A-Z])..(.*)[aeiouy]$", name)
|
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.