[Halld-offline] zero field

[David Lawrence]

Hi Matt,

  Sorry this has cost you so much time. You’re the first person to
report this as an issue in the 6 months since it was deployed. I’ll
go ahead and put in the code to generate and check the md5
checksum whenever a program is started so that an error can
be flagged if there is a mismatch.

Regards,
-David

On Jul 18, 2014, at 10:15 AM, Matthew Shepherd <mashephe at indiana.edu> wrote:

> 
> With bits and pieces from 3 different people,  I think 
> I've figured this out...  gggrrrrrr!
> 
> Mike Staib suggested my log seemed to indicate my field doesn't have
> enough z points.
> 
> It seems like jana is using JANA_RESOURCE_DIR to cache fields.  (I got
> this from Paul.. I've never set this, but grep and reading jana source 
> tells me it is set by default to /tmp/username/resources.)
> 
> If I go to that directory and delete it and rerun bfiled2root, I get 
> a full field.
> 
> What happened?  Here's my theory:
> 
> I ran a job and that job chose to download the field.  This
> is the first time consuming thing that happens in a job.  If, 
> during the field download you kill the job with ctrl-c then 
> you are left with a partial field.
> (I tested this out and was able to repeat it.)
> 
> I must have been unlucky and hit ctrl-c on the job that
> tried to download the field.  Note this is normal for must users.
> It is easy to execute a command accidentally or realize just
> after you press return that you didn't specify all the arguments
> that you wanted.
> 
> This is a really nasty behavior because every subsequent job
> then just reads this partial field and never prints any message
> or error.
> 
> Can we put some sort of check in the field?  Write the number
> of points in the file first.  And then on read back when there
> isn't than many points abort with an error.
> 
> nasty nasty nasty... that cost Paul and me a ton of time
> this week
> 
> Matt
> 
> ---------------------------------------------------------------------
> Matthew Shepherd, Associate Professor
> Department of Physics, Indiana University, Swain West 265
> 727 East Third Street, Bloomington, IN 47405
> 
> Office Phone:  +1 812 856 5808
> 
> On Jul 18, 2014, at 7:18 AM, David Lawrence <davidl at jlab.org> wrote:
> 
>> 
>> Hi Matt,
>> 
>>  The output looks right. What happens if you run the bfield2root utility? This should
>> be built as part of the default sim-recon build. (Source is in $HALLD_HOME/src/programs/Utilities/bfield2root)
>> 
>> Draw the field map in ROOT using:
>> 
>>> bfield2root
>>> root bfield.root
>> root [1] Bz_vs_r_vs_z->Draw("colz")
>> 
>> Also, how are you checking that the field map is returning zeros?
>> 
>> Regards,
>> -David
>> 
>> On Jul 17, 2014, at 9:49 PM, Matthew Shepherd <mashephe at indiana.edu> wrote:
>> 
>>> 
>>> Hi all,
>>> 
>>> Paul and I have been trying to understand why I cannot
>>> get the example analysis software working and we seem
>>> to have traced the problem down to the fact that the 
>>> magnetic field map is returning a zero field.
>>> 
>>> Does anyone know how to debug this?  The startup
>>> of the job suggests all is OK (I think):
>>> 
>>> JANA >>URL: sqlite:////home/s4/mashephe/gluex/ccdb.sqlite
>>> JANA >>context: default
>>> JANA >>Reading Magnetic field map from Magnets/Solenoid/solenoid_1350_poisson_20
>>> 130925 ...
>>> Nx=251 Ny=1 Nz=43 )  at 0x7f46720a0ce0
>>> Fine-mesh evio file does not exist.
>>> Constructing the fine-mesh B-field map...
>>> rmin: 0 rmax: 88.5 dr: 0.1 zmin: 0 zmax: 600 dz: 0.1vg.: 0.0Hz)     
>>> Number of points in z = 6000
>>> Number of points in r = 885
>>> JANA >>10599 entries found (Created Magnetic field map of type DMagneticFieldMap
>>> 
>>> I'm using:
>>> 
>>> sim-recon-2014-06-30
>>> ccdb_1.02
>>> hdds-2.1
>>> jana_0.7.1p3
>>> 
>>> and a ccdb.sqlite file from July 14 (copied from Mark's web page link that day).  I've also
>>> tried the ccdb.sqlite file from dc2 conditions.
>>> 
>>> Matt
>>> 
>>> 
>>> ---------------------------------------------------------------------
>>> Matthew Shepherd, Associate Professor
>>> Department of Physics, Indiana University, Swain West 265
>>> 727 East Third Street, Bloomington, IN 47405
>>> 
>>> Office Phone:  +1 812 856 5808
>>> 
>>> 
>>> _______________________________________________
>>> Halld-offline mailing list
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>> 
>