[Clas_cascades] st offset in ffread

[Zhiwen Zhao]

Hi, Paul

I dig out an old email ( see bottom), in which you suggest it should be
***********************************
TGPOS 0.0 0.0 0.0    #IT MUST BE THIS!!!!! (real target position read 
from caldb)
STZOFF -50.0
***********************************

I am looking into this because I have some timing problem for my simulation
Particle vertex position and timing all look fine
But to match particle vertex time calculated by TOF, the event starttime 
has to be about -56/c_light, while the target center is at -50

I am wondering if it can caused by two things:
1. the setting in GSIM as we discussed
2. The use of right runindex

For 2, eg3 should use calib_user.RunIndexEG3Sim for gsim and gpp and 
user_ana
I tried "setenv CALDB_RUNINDEX calib_user.RunIndexEG3Sim", but it 
doesn't make it happen, they are still use RunIndex
Any idea?

Thanks

Zhiwen


On 4/7/2010 11:08 AM, Paul Mattione wrote:
> It is correct.  For some reason gsim doesn't want/need the additional 
> 4.06 cm offset that caldb has.  Maybe it already takes it into 
> account.  Both g11 and g13 are doing it that way and it works fine.
>
>  - Paul
>
> On Apr 7, 2010, at 4:06 AM, Zhiwen Zhao wrote:
>
> Dear Eg3er
>
> I notice that the st offset in CALDB is -45.06
> But it's -41 in our general ffread file, eg.
> http://clasweb.jlab.org/rungroups/eg3/wiki/index.php/Ffread_file_for_xi-pi- 
>
> Is that a mistake or something else?
>
> Thanks
>
> Zhiwen
> _______________________________________________
> Clas_cascades mailing list
> Clas_cascades at jlab.org
> https://mailman.jlab.org/mailman/listinfo/clas_cascades
>
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I'm pretty sure the difference is automatically accounted for: i.e. gsim 
ALREADY automatically shifts it by that amount, so if you set STZOFF to 
-45.06 it'll shift it twice (to -40.12) and it'll be messed up.  I got 
this understanding from Pawel who got it from Franz so I'm pretty sure 
it's correct, but feel free to ask others.

  - Paul

On Apr 21, 2008, at 12:52 PM, Zhiwen Zhao wrote:

hi, Paul

Where do you get the STZOFF -50.0?
It's currently -45.06 in database.

Best Regards


             Zhiwen Zhao


Paul Mattione wrote:
No, I adjusted for eg3.
- Paul
On Apr 18, 2008, at 5:27 PM, Zhiwen Zhao wrote:
Thanks Paul
But those values you mentioned are for g13, not eg3, right?
Best Regards
            Zhiwen Zhao
Paul Mattione wrote:
Some ST/Target info is read from your ffread & tcl files, some from the 
runindex.  You need to make sure that the target & st positions in the 
caldb are the correct values for eg3 in runs 1->10.
In ffread card for gsim:
TGPOS 0.0 0.0 0.0    #IT MUST BE THIS!!!!! (real target position read 
from caldb)
STZOFF -50.0
In tcl file for user_ana:
set TargetPos(3) -50.0;
set TargetLen 40.0;
#ST INFO GRABBED FROM caldb!!!!!
I had to sort through all this crap for g13.  I hope this helps.
- Paul
On Apr 18, 2008, at 1:22 PM, Zhiwen Zhao wrote:
Hi, Hovanes
If in one's analysis code only eloss is related to reading constants 
CALDB, it will be ok if just let eloss called with any real run number 
in eg3 run period with main Runindex because the target and St 
parameters were unchanged for the whole eg3 run period.
This applies to real data and simulated data.
In this case, runindexeg3a wouldn't be needed.
Please let me know if my understanding is right.
1. GSIM need the ST parameters in ffread card, not in CALDB
2. cooking need the ST parameters in CALDB, not in the tcl file.
So if use main Runindex to cook simulated data, the ST bank won't be 
built correctly?
Thanks
Best Regards
          Zhiwen Zhao
Hovanes Egiyan wrote:
Hi Zhiwen,
I looked at your web page.
The DB entries were copied to runindexeg3a to be able to run private 
analysis
codes requiring eloss corrections.  The target and ST parameters are 
important
for eloss. Cooking and GSIM should be run with the main  runindex 
table.  The
target and ST parameters in GSIM are supposed to be set in FFREAD card.
The only possible issue is the ST reconstruction of the GSIM data (which 
I personally
do not use).  The entries in the main runindex for ST for run 10 will 
not be
correct.    I think we should create a runindex with a complete set of 
tables
of main runindex, but change the ones that are red and related to the 
target and
the start counters for run 10.
I was out of town, I do not know what exactly was discussed.
eloss is not applied  in  cooking, the momenta from cooked files
should be corrected for the energy loss and momenta.
Hovanes.
Zhiwen Zhao wrote:
hi, Hovanes

We had a discussion about if eloss has been implemented in the cooking 
code or cooking procedure.
Can you clarify that?

Thanks

Best Regards


         Zhiwen Zhao

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