Re: brat tag 21-1-27, mult classes updated

From: Christian Holm Christensen (cholm@hehi03.nbi.dk)
Date: Tue Nov 13 2001 - 05:46:39 EST

  • Next message: Ian Bearden: "RE: brat tag 21-1-27, mult classes updated"

    Hi Steve, 
    
    On Mon, 12 Nov 2001 09:42:31 -0600
    "Stephen J. Sanders" <ssanders@ku.edu> wrote
    concerning "brat tag 21-1-27, mult classes updated":
    > Hi,
    
    > I've just made a number of modifications to the multiplicity and
    > centrality classes to incorporate a 200GeV calibration.  I have also
    > updated the ZDC classes to add the cfd methods that Hiro has worked
    > on.  Since the ZDC modifications change the date structure (with the
    > addition of a cfd vertex), I have bumped the ClassDef for BrZdcRdo
    > to 4.  Although the CFD ZDC vertex has a broader distribution with
    > respect to the TPM1 vertex, it is found to be more reliable at low
    > ZDC multiplicity since there is less of a slewing correction.  For
    > the multiplicity calibration we only use the zdc vertex when a BB or
    > TPM1 vertex can not be found, so the slewing correction is a
    > significant issue.
    > 
    
    > The si/tile/mult classes now all look for a run number from the run
    > manager in their Init methods.  They should be selecting a
    > reasonable calibration depending on run number.  
    
    Argh! Modules should not, I repeat not, look for calibrations
    themselves!  They must, I repeat must, assume that all calibrations
    are as they should be, otherwise chaos and mayhem will quickly insue!
    This is due to the fact that calibrations are managed, and as such,
    Modules can not, and must not modify that data!  Imagine what happens
    if you certainly start reading in at two places in the code -
    unbeknownst to your modules, they could very well have the wrong
    calibrations.  
    
    So far, the calibrations for the TMA and SMA have been read from ASCII
    files installed in <prefix>/share/brat/params/mult, even though the
    calibrations for last years data has been in the database for  quite
    some time now.  When you you commit the 2001 calibrations to the
    database, we should immidiatly switch to that interface and remove the
    old, useless, ASCII files. 
    
    The proper way to do things for the time being, using the ASCII files,
    is to read the ASCII files from your configuration script.  This
    works, since the temporary calibration classes are singletons.  Hence,
    you should have in your configuration script
    
      BrSiTmpCalibration::Instance()->ReadASCIIFile(runOption->GetValue());
      BrTileTmpCalibration::Instance()->ReadASCIIFile(runOption->GetValue());
      BrMultCentTmpCalibration::Instance()->ReadASCIIFile(runOption->GetValue());
    
    If you're still not using configuration scripts (sigh), then you need
    to put these lines into your program somewhere.  
    
    I will change the classes so that they do not read the ASCII files
    themselves ASAP.  I will ofcourse announce that on the list.   
    
    > For the 200 GeV data, the calibration is taken from run 4640.  I
    > will be adding calibrations for the later runs as soon as possible.
    
    Am I to understand, that the pedestal, pedestal width, gap, pulser,
    and gain calibrations in that file is good?  If so, I'll start an
    SDE centrality calibration ASAP.  
    
    > However, let me know if there is a specific later run for which you
    > need a centrality and I try to develop one.  In general, I believe
    > that only the pedestals are likely to shift significantly
    > run-to-run, although there have been isolated cases of detector
    > element going bad.
    
    Erh, shouldn't we at least check that all the parameters are stable? 
    
    Yours, 
    
    Christian Holm Christensen -------------------------------------------
    Address: Sankt Hansgade 23, 1. th.           Phone:  (+45) 35 35 96 91 
             DK-2200 Copenhagen N                Cell:   (+45) 28 82 16 23
             Denmark                             Office: (+45) 353  25 305 
    Email:   cholm@nbi.dk                        Web:    www.nbi.dk/~cholm
    



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