Re: [BLAST_ANAWARE] Error Propagation in ROOT -- beware!

From: Chris Crawford (chris2@lns.mit.edu)
Date: Thu Apr 22 2004 - 11:36:18 EDT


Hi Adrian,
  I apologize; I went back over the error calculations with Jason, and
as long as you assume Poisson statistics, the ROOT propogation works
fine (coincidentally). The only thing you have to worry about is if
you do background subtraction, because then the corrected yields don't
have sqrt(n) errors anymore.
--Chris

Adrian T Sindile wrote:

>Hi, Chris!
>Per your suggestion, I tried Jason's GetAsymmetry() function.
>I am pretty sure I get the same error bars using both my older way and his
>ROOT contributed function.
>Attached is a plot of left dA/A and right dA/A obtained for 26 KCoulombs
>integrated charge from December (about two weeks of running - between
>December 9th and December 23rd).
>
>Adrian
>
>
>
>>>Try jason's GetAsymmetry() function, and I'm pretty sure you will get a
>>>different result. The naming doesn't matter; just that leftThPlus is
>>>used both in the numerator and denominator.
>>>
>>>
>>I will try Jason's function - but please note that even show_ep_asym.C
>>written by Jason does not use that function...
>>
>>I will probably end up propagating everything by hand, just to make sure
>>there are no questions about it.
>>Cheers!
>>
>>Adrian
>>
>>
>>
>
>
>
>
> ------------------------------------------------------------------------
>



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