| sFilter {tm} | R Documentation |
Filter metadata by special statements.
sFilter(object, s, ...)
object |
a TextDocCol to be the filter applied to. |
s |
a statement of format "tag1 = 'expr1' & tag2 =
'expr2' & ...". |
... |
arguments passed over by calling functions. |
The statement s models a simple query language. It consists of
an expression as passed over to a data frame for subsetting. Tags in
s represent metadata variables. Variables only available at
document level are shifted up to the data frame if necessary. Note
that the metadata tags for the slots Author, DateTimeStamp,
Description, ID, Origin and Heading are
author, datetimestamp, description,
identifier, origin and heading, respectively, to
avoid name conflicts.
A Boolean vector to represent the subset of the DMetaData
(extended for shifted up variables) data frame as specified by the
statement.
Ingo Feinerer
## Load example dataset data(crude) ## Statement Filter returning TRUE for document with ID 127 and heading DIAMOND ... sFilter(crude, "identifier == '127' & heading == 'DIAMOND SHAMROCK (DIA) CUTS CRUDE PRICES'")