grep2 {JATSdecoder}

grep2

Description

Extension of grep(). Allows to identify and extract cells with/without multiple search patterns that are connected with AND.

Usage

grep2(pattern, x, value = TRUE, invert = FALSE, perl = FALSE)

Arguments

pattern

Character vector containing regular expression as cells to be matched in the given character vector.

x

A character vector where matches are sought, or an object which can be coerced by as.character to a character vector. Long vectors are supported.

value

Logical. If FALSE, a vector containing the (integer) indices of the matches determined by grep2 is returned, and if TRUE, a vector containing the matching elements themselves is returned.

invert

Logical. If TRUE return indices or values for elements that do not match.

perl

Logical. Should Perl-compatible regexps be used?

Value

grep2(value = FALSE) returns a vector of the indices of the elements of x that yielded a match (or not, for invert = TRUE). This will be an integer vector unless the input is a long vector, when it will be a double vector.

grep2(value = TRUE) returns a character vector containing the selected elements of x (after coercion, preserving names but no other attributes).

See Also

grep

Examples

x<-c("ab","ac","ad","bc","bad")
grep2(c("a","b"),x)
grep2(c("a","b"),x,invert=TRUE)
grep2(c("a","b"),x,value=FALSE)