Most expression provided will be used to filter out detections based on
calculated parameters.
If the name of an environmental variable added using
matchEnvData,AcousticStudy-method is provided, will filter to only events with environmental
variables matching those conditions.
If a provided logical expression uses
"species" or "Species", then events will be filtered using the
species present in the $id of the species slot of each event.
If a provided logical expression uses "database" or "Database",
then only events with databases matching the expression in files(.data)$db
will remain
If a provided logical expression uses "detector" or "Detector", then
only detections from detectors with names matching the expression will remain in
events. Any events left with no detections will be removed.