From: 	  roethel@slac.stanford.edu
	Subject: 	Adding a skim filter to an analysis job
	Date: 	March 18, 2005 4:42:14 PM PST
	To: 	  hearty@slac.stanford.edu

  Hi Chris,

I understand you are writing an update to your workbook for offline users 'receipe' and I thought you may be interested in a how-to to add a skim filter to an analysis job (which you probably know how to do).

  The background is the following. Some skims (e.g. the TwoPhotonPentaquark skim I'm running on) do not produce and store a tag bit for filtering the data, but the filtering is programmed in a particular filter module. The disadvantage is that reproducing these skims (e.g. when running on SP signal) can not easily be simulated by adding tag filters like in your example of the Jpsitoll skim or adding simple filters on the integers and floats stored in the tag database of an event.
  The most straight forward solution to this problem is to simply turn on the actual filter used for producing the skims. The only real thing needed is
   a) make sure the version of FilterTools is the same as using in
      skimming - if not it needs to be checked out and compiled.
   b) add the filter module to AppUserBuild - that can even be done for
      BtaTupleApp (which is what I did).
   c) add the FilterModule to the path - needs some simple hacking in
      BetaMiniSequence.tcl.

  Once the filter module is registered with the application it can then be turned on or off as needed, preferrably by settinga FwkCfgVar.

  If you think this is in general useful for others I can write something up a bit more detail.

  - thanks,
  Will