R: Filter and Index Functions on Corpora

tm_filter {tm}

R Documentation

Filter and Index Functions on Corpora

Description

Interface to apply filter and index functions to corpora.

Usage

## S3 method for class 'Corpus'
tm_filter(x, ..., FUN, doclevel = TRUE, useMeta = FALSE)
## S3 method for class 'Corpus'
tm_index(x, ..., FUN, doclevel = TRUE, useMeta = FALSE)

Arguments

`x`	A corpus.
`...`	Arguments to `FUN`.
`FUN`	A filter function returning a logical value.
`doclevel`	Logical. If the document level flag is set `FUN` is applied to each element of `x`, otherwise `FUN` is applied to `x` itself. If `FUN` has an attribute `doclevel` its value will be automatically used.
`useMeta`	Logical. Should `DMetaData` be passed over to `FUN` as argument?

Value

tm_filter returns a corpus containing documents where FUN matches, whereas tm_index only returns the corresponding indices.

Examples

data("crude")
# Full-text search
tm_filter(crude, FUN = function(x) any(grep("co[m]?pany", x)))