R: Check if text contains a certain pattern

txt_contains {udpipe} | R Documentation

## Check if text contains a certain pattern

### Description

Look up text which has a certain pattern. This pattern lookup is performed by executing a regular expression using `grepl`.

### Usage

    txt_contains(x, patterns, value = FALSE, ignore.case = TRUE, ...)

### Arguments

`x` | a character vector with text
`patterns` | a regular expression which might be contained in `x`, a vector of these or a list of pattern elements where the list elements `include` and `exclude` indicate to find a pattern in `x` while excluding elements which have another pattern
`value` | logical, indicating to return the elements of `x` where the pattern was found or just a logical vector. Defaults to FALSE indicating to return a logical.
`ignore.case` | logical, if set to `FALSE`, the pattern matching is case sensitive and if TRUE, case is ignored during matching. Passed on to `grepl`
`...` | other parameters which can be passed on to `grepl` e.g. fixed/perl/useBytes

### Value

a logical vector of the same length as `x` indicating if one of the patterns was found in `x`.
Or the vector of elements of `x` where the pattern was found in case argument `value` is set to `TRUE`

### See Also

`grepl`

### Examples

    x <- c("The cats are eating catfood",
           "Our cat is eating the catfood",
           "the dog eats catfood, he likes it",
           NA)
    txt_contains(x, patterns = c("cat", "dog"))
    txt_contains(x, patterns = c("cat", "dog"), value = TRUE)
    txt_contains(x, patterns = c("eats"), value = TRUE)
    txt_contains(x, patterns = c("^The"), ignore.case = FALSE, value = TRUE)
    txt_contains(x, patterns = list(include = c("cat"), exclude = c("dog")),
                 value = TRUE)
    txt_contains(x, "cat") & txt_contains(x, "dog")

[Package udpipe version 0.8.8 Index]