[Halld-physics] pull distributions

[Richard Jones]

Curtis and all,

It might help to have a more consistent nomenclature.  What Simon seems to be describing are called "residuals".  Pulls are the deltas that result from constrained fitting, like a kinematic fit.

-Richard J.


On 10/25/2010 1:26 PM, Curtis A. Meyer wrote:
> Hi Everyone -
>
>      I found a chapter of a PhD thesis that talks about
> kinematic fitting. Section 6.1.2 talks about the pull distributions and
> formula
> 6.6 is as I remember it with the denominator having a difference inside the
> square root.
>
>      I also recall many years ago looking into what happens when the
> error matricies
> are not diagonal. The denominator is defined only using the diagonal
> elements
> of the covariance matrix, both for starting values and the fit values.
>
>      With regard for Simon's work, where he is looking at individual
> tracks, I am
> not 100% sure how to apply this though. The error matrix is the result
> of the fit.
> In Jake's work, it is clearer a we have the pull's from the tracking,
> and then the
> improved pulls after the kinematic fit.
>
>      I have placed the chapter (6) on the portal as GlueX-doc-1635:
>
>      Other references include:
>
>      Eadie, W. T. et al., Statistical methods in experimental physics
> (North-Holland, Amsterdam, 1986).
>
>     V. Blobel, Least squares methods, p. I 27, in Bock, R. K. et al.
> (eds.), Formulae and methods
>     in experimental data evaluation with emphasis on high energy physics.
> (European Phys. Soc.,
>     1984)
> curtis
>


-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4092 bytes
Desc: S/MIME Cryptographic Signature
Url : https://mailman.jlab.org/pipermail/halld-physics/attachments/20101025/ce4c931b/attachment.bin