tmMap-methods {tm} | R Documentation |
Methods for function tmMap
in package tm.
FUN
onto each element
of object
. Note that document specific metadata (i.e.,
DMetaData(object)
is automatically passed to
FUN
as argument DMetaData
. FUN
must be a
function which returns a TextDocument
. If lazy
is
set, so-called lazy mapping is activated, i.e., mappings are
delayed until the documents' content is accessed. Lazy mapping is
useful when working with large corpora but only a few documents
are accessed, as it avoids applying the mapping to all elements in
the document collection.Please be aware that lazy transformations are an experimental feature and change R's standard evaluation semantics.
See getTransformations
for available transformations
shipped with tm. See materialize
for manually
materializing lazy transformations.
data("crude") tmMap(crude, stemDoc) headings <- function(object, ...) { new("PlainTextDocument", Heading(object), Cached = TRUE, DateTimeStamp = Sys.time(), ID = ID(object), Language = Language(object)) } inspect(tmMap(crude, headings))