LHCb Wiki Pages - davinci

alltracks

Anonymous (anonymous@undisclosed.example.com) — 2009-12-23T08:49:57+00:00

How to include all track types in an analysis Problem When specifying the input for CombineParticles, only the specified types of tracks are take into account (most of the time LongTracks). However, it may be beneficial to look at different track types at the same time.

datatypes

Anonymous (anonymous@undisclosed.example.com) — 2012-04-25T10:35:01+00:00

Find Available Data-Types Lbglimpse __known_datatypes__ DaVinci

davinci

Anonymous (anonymous@undisclosed.example.com) — 2012-04-25T10:29:19+00:00

DaVinci Analysis framework DaVinci FAQ * Simple Example - An complete example of a very simple selection algorithm. Good for getting started. * Write a miniDST - How to write out a subset of events in DaVinci and store them in a new DST-file. * Samples - A little overview of the samples one can use for an analysis.

dbtags

Anonymous (anonymous@undisclosed.example.com) — 2012-04-26T12:48:17+00:00

Database tags (CondDB and DDDb) Data is produced or processed with different database tags. For example if the VELO was open, the database tag needs to specify that. Find the correct tags for your data Look at your datafiles from the bookkeeping: the file names contain the dataset number. For the following datafile the dataset number is 5630.

mcassoc

Anonymous (anonymous@undisclosed.example.com) — 2010-07-16T12:02:42+00:00

How to implement a MC associator Idea Sometimes it may be necessary to associate a Particle to a MCParticle (truthmatching) in a self written C++-code. Implementation To associate a MCParticle to a Particle in DaVinci, implement the following (works for DaVinci v25r4).

minidst

Anonymous (anonymous@undisclosed.example.com) — 2009-01-16T20:00:12+00:00

How to write a miniDST Idea When analyzing a large sample of events, it may be useful to write a subsample of events (which may have passed) in a new DST file, which then can be used later on and is looped through faster than the original one. Code

particletable

Anonymous (anonymous@undisclosed.example.com) — 2014-03-06T13:06:09+00:00

Particle Table for DecayDescriptor You find the full table in How to For the DecayDescriptor in CombineParticles in DaVinci, you need to know the name of the particles which can be used. This list can be dumped the following way on lxplus: Dump Text File

positiveid

Anonymous (anonymous@undisclosed.example.com) — 2009-06-17T09:22:50+00:00

Revert particle ID to a positive number in DecayTreeTuple Idea It may sometimes be useful to store particles always under the same label, for instance always as muminus and not as muplus and muminus in the nTuple. This will allow to chain or merge the root files in an easy way afterwards. A simple example may be:

removetthits

Anonymous (anonymous@undisclosed.example.com) — 2011-02-11T21:28:22+00:00

Removing TT Hits Idea Removing TT hits from long tracks can be a good check to see effects which are caused by the TT. TO BE FINISHED WHEN IT WORKED AS I THOUGHT How to Add the following two source files f.ex. to Tr/TrackTools. TrackRemoveSTIDs.cpp

samples

Anonymous (anonymous@undisclosed.example.com) — 2009-07-02T12:45:39+00:00

Particle Samples (DC06) Idea To perform an analysis in DaVinci, several types of samples can be used, which represent tighter or looser restrictions to the selection of the particles. The following notes are just a copy of the comments in the StandardDC06Options.opts

track_types

Anonymous (anonymous@undisclosed.example.com) — 2012-06-04T12:29:29+00:00

Find available track types The track types are defined in the header file for the LHCb::Track class. You find the relevant infomartion in the Doxygen for DaVinci. Since the track type is of type enum, the first name corresponds to 0, the second to 1, and so on. List of types

tthitslongtrack

Anonymous (anonymous@undisclosed.example.com) — 2010-10-22T15:43:55+00:00

How to cut on number of TT hits on tracks Problem Some of the long tracks don't have TT hits. However, it may be useful to distinguish in an analysis long tracks with and without TT hits. Code In your Combine Particles or wherever LoKi cuts can be applied, do:

xmlcounters

Anonymous (anonymous@undisclosed.example.com) — 2010-03-26T15:17:57+00:00

How to get XML counters for your algorithms Problem At the end of the stdout file all the counters are listed. Because the stdout can be very big it is easier to just have these counters for each algorithm in one file. The XML counters are stored in summary.xml in your outputsandbox, where the stdout is as well.