Count matches for multiple patterns across a character vector

Count matches for multiple patterns across a character vector

Usage

grepns(patterns, x, ignore.case = TRUE, rowperx = FALSE, count1perx = TRUE)

Arguments

patterns

vector of 1+ patterns to search for, passed one at a time to gregexec()

x

a vector of character strings to search within

ignore.case

passed to gregexec()

rowperx

whether to return a matrix with one row per element of x and one column per pattern, or instead return a vector with one element per pattern summarizing across all of x

count1perx

whether to count only 1 match per pattern per element of x, or to count all matches (i.e., if there are 3 matches for a pattern in one element of x, count as 1 or 3)

Value

If rowperx = TRUE, a matrix with one row per element of x and one column per pattern. If rowperx = FALSE, a vector with one element per pattern summarizing across all of x.

See also

grepns() grepls() find_in_files() found_in_files() found_in_N_files_T_times() grep_lines()

Examples

 grepn("x", c("0 abc", "1 uppercase X", "1 xyz", "2 xx", "3 x x x"))
 grepn("x", c("0 abc", "1 uppercase X", "1 xyz", "2 xx", "3 x x x"), ignore.case = FALSE)

 grepns(c("x", "y"), c("yes", "yx", "this 1 has some x x xxxxx"))
 grepns(c("hi", "other", 'x'), c("said hi ther hi hi hi e", 'hi', 'another', 'none'),
         rowperx = TRUE, count1perx = TRUE)
 grepns(c("hi", "other", 'x'), c("said hi ther hi hi hi e", 'hi', 'another', 'none'),
         rowperx = FALSE, count1perx = TRUE)
 grepns(c("hi", "other", 'x'), c("said hi ther hi hi hi e", 'hi', 'another', 'none'),
         rowperx = TRUE, count1perx = FALSE)
 grepns(c("hi", "other", 'x'), c("said hi ther hi hi hi e", 'hi', 'another', 'none'),
         rowperx = FALSE, count1perx = FALSE)

 grepls(c("hi", "other", 'x'), c("said hi ther hi hi hi e", 'hi', 'another', 'none'),
   rowperx = TRUE)
 grepls(c("hi", "other", 'x'), c("said hi ther hi hi hi e", 'hi', 'another', 'none'),
   rowperx = FALSE)