[Lowq] DC calibration issues

[seema at jlab.org]

Hello Everyone,
Please have a look at the attached file dc_mean.pdf. This table compares
the time residual means for run number 61695. The numbers in the
parentheses are from dc3 software. These are the numbers from my last
iteration. I could not run trk_mon on this new cooked file because TBLA
bank was not there in this new version of dc cooking. We still have some
disagreement. In dc3 software we have one more constraint before
calculating the mean and that is :
// Make sure narrow and wide didn't switch
   if(PAR[2]>PAR[5]){
      for(i=0;i<3;i++){
         tmp=PAR[i];
         PAR[i]=PAR[i+3];
         PAR[i+3]=tmp;
      }
   }

   *sigma_narrow    = 1.0E4*PAR[2];
   *sigma_wide      = 1.0E4*PAR[5];
   *amplitude_ratio = PAR[0]/PAR[3];
   *mean            = ((PAR[0]*PAR[1]*PAR[2]) + (PAR[3]*PAR[4]*PAR[5]))
                                        /((PAR[0]*PAR[2]) +(PAR[3]*PAR[5]));
I am not sure if we have this condition implemented in user_ana.
Please let me know if you have any questions.
Best regards,
Seema


> Hi Seema,
>
> This can have significant effect.
> What are the values in pmin and pmax arrays?
> The initial parameters are close enough, the ratio of the first and
> fourth parameters should be same,
> the other parameters should start
> with the same values. Also I  am
> not sure if the number of parameters
> matters in these calls, but I would make them identical too.
>
> I would suggest changing user_ana
> to match the calibration procedure source.
>
> Hovanes
>
>
>
> Sent from my iPhone
>
> On Dec 5, 2010, at 5:01 PM, seema at jlab.org wrote:
>
>> Hello Everyone,
>> I have checked once again the fitting function used in dc3  and user_ana
>> software. Although double gaussian is used in each case but the starting
>> parameters are not allowed to vary freely in user_ana and that may be
>> the
>> reason for inconsistency in time residual means.
>>
>> Functional form used in user_ana
>>
>> call hfithn(hid,'G+G','QB',0,ggpar,step,pmin,pmax,eggpar,chi2)
>> ggpar(1) = 50000
>> ggpar(2) = 0.
>> ggpar(3) = 0.02
>> ggpar(4) = 10000
>> ggpar(5) = 0.
>> ggpar(6) = 0.1
>>
>> Functional form used in dc3
>>
>> hfithn(HID,"g+g","Q",6,PAR,STEP,PMIN,PMAX,SIGPAR,&CHISQ);
>>
>> PAR[6] = {500.0, 0.0, 0.0300, 50.0, 0.0, 0.100}
>>
>> Please notice the extra  'B' option selected in user_ana and also the
>> starting parameters are different!
>>
>> Best regards,
>> Seema
>>
>>
>>> Dear all,
>>>
>>> due to various activities, Hall closing, PAC deadline and so on,
>>> tomorrow's eg6 meeting is canceled.
>>>
>>> Stepan
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>>
>>
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