Hints and Tips

In this section are listed a few hints and tips to help new users.

• Always put your commands into command files rather than type directly into SNOMAN. That way you keep a permanent record of what you have done and can easily replay it. Don't forget to add comments!

• You can decide which processors to run using the command $processor_list for example:-

  $processor_list ' MCO FTT ANL OUT END '

  For a list of processors and support systems in SNOMAN see:-

  Companion/Software Structure/List of Structure Diagrams

  Which gives a brief sumary of each. For more details just keep reading this manual!

• The order in which processors appear in a $processor_list command is, important. Processors are called for each event in the exact order given on the $processor_list command. Note:-
  1. It is up to the user to ensure that the list is sensible!
  2. Processors can appear in the list more than once.

  Event processing terminates as soon as a processor fails, unless it is a fitter or classifier, as failures here are not considered fatal to further processing. The default setting is:-

• Normally only one of Event Input (INP) or Monte Carlo (MCO) is switched on for any one job. However is permitted to switch on both, although this should only be done with care. The prime use is as follows:-

  $processor_sequence $user_controlled
  $processor_list ' INP PRU MCO FTT ANL END '
  
  $prune_ev $drop       * Drop everything but the MC subtree
  $prune_dsml $drop
  
  $mc_num_seed_vx 0     * Don't add any new seed vertices.
  
  $pmt_nois_rate 0.     * Switch off noise (already added).
  

  The above inputs MC events, prunes away the EV and DSML and then passes them to MCO again. In this case MCO sees that there is nothing new to add, as there are no new seeds, and just repeats the DAQ. The event is then fit and analysed as normal.

  Note, without the line:-

  $mc_num_seed_vx 0 * Don't add any new seed vertices.

  MCO would add more seeds to the event and evolve them, which may be what you want, or possibly not!

• If using MCO, it is a good idea to follow it by UCL PCK UPK CAL to uncalibrate, pack, unpack and calibrate the data, for example:-

  $processor_list ' MCO UCL PCK UPK CAL FTT ANL OUT END '

  This subjects the data to the same digitising processes as the real data. For more information see 13.6 Do not try a short cut, such as PCK UPK or UCL CAL, they will not work properly.