RE: [ccp4bb]: I to F's

[Alexey Bochkarev <Alexey-Bochkarev@ouhsc.edu>]

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> > For example; in CNS
> > 
> > if I >= 0 and sigI < I:
> > 
> >       F = sqrt(I)
> >       sigF = F - sqrt(I - sigI)
> > 
> > if I >= 0 and sigI >= I:
> > 
> >       F = sqrt(I)
> >       sigF = F
> > 
> > if I < 0:
> > 
> >       F = 0
> >       sigF = 0
	[Alexei Botchkarev]  A rationale of such  conversion in CNS is not
clear for me.
	Starting with
	                     I + SigI = ( F + SigF ) **2

	and assuming unbiased distribution:

	                     I = F**2

	one can easily get:

	                     SigF = sqrt( I + SigI ) -sqrt( I )

	which is valid for all I,SigI > 0

	Alexey

Alexey Bochkarev, Assistant Professor
Dept. of Biochemistry and Molecular Biology	
Univ. of Oklahoma Health Sciences Center, BRC-466	
P.O. Box 26901, Oklahoma City, Oklahoma  73190
Phone:	(405) 271-8346
FAX :	(405) 271-3910
mailto:Alexey-Bochkarev@ouhsc.edu
http://xtliris.ouhsc.edu/alexey.htm

>