[G12] energy corrections

[Paul Eugenio]

Yes, this makes sense.  Floats have precision of 6 decimals whereas doubles have 15 decimal precisions.  While we are performing our calculations as double precisions, we are saving them to disk as floats.


--
Prof. Paul Eugenio
Florida State University
Department of Physics
Tallahassee, Florida,  USA 32306

(850) 325-0314
eugenio at fsu.edu




On Feb 16, 2012, at 8:47 AM, Johann Goetz wrote:

> Actually those differences you see are because the 32bit floating point numbers in the BOS files are only good to 5 digits at best, and the paddles' widths are about 5 MeV anyways.
> 
> On Wed, Feb 15, 2012 at 3:03 PM, Mukesh Saini <msaini at admin.fsu.edu> wrote:
> Hello,
> 
> I checked a few runs in my data and compared the photon energies in my
> data-ntuples against  the energies provided in the file:
> 
> /group/clas/parms/pcor/g12/tagger_energies_reported_by_tagr_bank.txt
> 
> Some of the photon energies in my data-ntuples are off by fractions of
> MeV (at most 0.5 MeV) from those in the file. I am guessing that is due
> to some tage correction function applied in CLASEvent. I couldn't find
> one during the first lookup of the code I did and I will look into this
> further.
> 
> In case, anyone is aware where this further correction gets applied, and
> if its necessary, We might have to add this correction in
> post-processing Beam Energy Corrections also. To reverse lookup and
> correct the tage paddle seems cumbersome if the photon-energies in the
> data-ntuple's don't match the ones in the table provided. I think I will
> just reskim my data to include the tage paddle number, if that is the case.
> 
> Mukesh.
> 
> On 02/15/2012 01:32 PM, Johann Goetz wrote:
> >
> > It describes the files and how to interpret them. Currently I only had
> > enough statistics to do 481 of the runs. I'm working on getting the
> > rest right now. Tomorrow, I intend to address momentum corrections and
> > I should have most of the
> 
> 
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> 
> -- 
> Johann T. Goetz, PhD.
> jgoetz at ucla.edu
> Nefkens Group, UCLA Dept. of Physics & Astronomy
> Hall-B, Jefferson Lab, Newport News, VA
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