Positive Likelihoods after Fit Minimimization.

karthik18495 commented 2 years ago

I have been trying to perform fits using AmpTools using the group build of halld_sim. The details of the Signal Events are below

Signal MC Events

I am trying to generate 1p state in Positive reflectivity PosRefl.
It is generated in a narrow mass range 1.10 - 1.15 GeV. and t range 0.15-0.30
A total of 10k events are generated.

Phasespace MC Events

1M events are generated in the same range as signal events

Fitting the generated signal

I fit the sample by initializing the production parameters to what was generated. This is for faster convergence.

When I fit, the fit converges with a positive LogLikelihood. Not sure what is going on.

The details of the software version are shown below

##################### Meta Info on software used ##############################
AMPTOOLS_HOME  /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/amptools/AmpTools-0.14.4  ; AMPTOOLS_VERSION  0.14.4
HALLD_SIM_HOME  /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/halld_sim/halld_sim-4.42.0  ; HALLD_SIM_VERSION  4.42.0
which fit : /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/halld_sim/halld_sim-4.42.0/Linux_CentOS7.7-x86_64-gcc4.8.5/bin/fit
which omegapi_plotter : /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/halld_sim/halld_sim-4.42.0/Linux_CentOS7.7-x86_64-gcc4.8.5/bin/omegapi_plotter
###############################################################################

The output log file is at volatile/halld/home/ksuresh/ampToolsFits/neutralb1/ClassicTests/TestingAmpTools/EmulatedSignal/OutputEmulated.log

To reproduce the problem in JLab's ifarm.

source /group/halld/Software/build_scripts/gluex_env_jlab.csh

Then, the source code is at

/lustre19/expphy/volatile/halld/home/ksuresh/ampToolsFits/neutralb1/ClassicTests/TestingAmpTools/EmulatedSignal

Commands to run.

./runAll.csh - will generate Signal, PhaseSpace and then performs fit
./runSignal.csh and ./runPhaseSpace.csh generate Signal and PhaseSpace
runFit.csh to fit the generated Signal and PhaseSpace sample.

Master branch of `AmpTools`

I confirmed that this issue still occurs with the master branch of AmpTools. To run with a Master version of AmpTools

source /work/halld/ksuresh/MY_HALLD_SIM_CPU2/setup_gluex.csh

and retry the runFit.csh.

mashephe commented 2 years ago

Karthik,

Is there a problem? Your fit log looks normal.

The value of -2 ln L is defined up to an arbitrary constant; therefore you should not expect the sign to take a particular value.

With version 0.14.4, which you are using, there were some changes to scaling of the likelihood so it may not be comparable with fits using previous versions.

The fit seems to converge... and the value of -2 ln L is less than what it was at initialization. I don't see anything that looks obviously unhealthy.

Matt

On Aug 17, 2022, at 5:22 PM, karthik suresh @.***> wrote:

I have been trying to perform fits using AmpTools using the group build of halld_sim. The details of the Signal Events are below

Signal MC Events

• I am trying to generate 1p state in Positive reflectivity PosRefl. • It is generated in a narrow mass range 1.10 - 1.15 GeV. and t range 0.15-0.30 • A total of 10k events are generated. Phasespace MC Events

• 1M events are generated in the same range as signal events Fitting the generated signal

• I fit the sample by initializing the production parameters to what was generated. This is for faster convergence. When I fit, the fit converges with a positive LogLikelihood. Not sure what is going on.

The details of the software version are shown below

##################### Meta Info on software used ##############################

AMPTOOLS_HOME /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/amptools/AmpTools-0.14.4
; AMPTOOLS_VERSION 0.14.4 HALLD_SIM_HOME /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/halld_sim/halld_sim-4.42.0
; HALLD_SIM_VERSION 4.42.0 which fit : /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/halld_sim/halld_sim-4.42.0/Linux_CentOS7.7-x86_64-gcc4.8.5/bin/fit which omegapi_plotter : /group/halld/Software/builds/Linux_CentOS7.7-x86_64-gcc4.8.5/halld_sim/halld_sim-4.42.0/Linux_CentOS7.7-x86_64-gcc4.8.5/bin/omegapi_plotter

############################################################################### The output log file is at volatile/halld/home/ksuresh/ampToolsFits/neutralb1/ClassicTests/TestingAmpTools/EmulatedSignal/OutputEmulated.log

To reproduce the problem in JLab's ifarm.

source /group/halld/Software/build_scripts/gluex_env_jlab.csh Then, the source code is at

/lustre19/expphy/volatile/halld/home/ksuresh/ampToolsFits/neutralb1/ClassicTests/TestingAmpTools/EmulatedSignal Commands to run.

• ./runAll.csh - will generate Signal, PhaseSpace and then performs fit • ./runSignal.csh and ./runPhaseSpace.csh generate Signal and PhaseSpace • runFit.csh to fit the generated Signal and PhaseSpace sample. Master branch of AmpTools

I confirmed that this issue still occurs with the master branch of AmpTools. To run with a Master version of AmpTools

source /work/halld/ksuresh/MY_HALLD_SIM_CPU2/setup_gluex.csh and retry the runFit.csh.

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karthik18495 commented 2 years ago

Oh OK sorry for the false alarm. I tried to compare it with previous fits. Just a question though, I run 25 random fits and in some of them the likelihoods are positive and others are negative. How would I rate these fits, How would I make sure which one of the fits among the 25 fits is the best?

mashephe / AmpTools