Filters

	Filters

A filter process an input event stream producing an output event file that contains a subset of parameters from a subset of the events in the input stream.

Filters consist of three components:

A gate that determines which events will be passed to the output file.
A list of parameters that determine which parameters are written for each event that makes the gate true.
A file to which the output events are written.

Filters are created and manipulated with the filter command.

Filters are created in the "disabled" state. When a filter is enabled, it opens its output file and starts writing filtered data. Separating the enable/disable from attaching data files allows you to produce an output file that is filtered data from several event files. To close the file associated with a filter, disable it.

At any time, you may modify any of the components of a filter (gate, parameterlist and filename).

See the filter section of the programming guide for a description of how to read back filtered data files.