Re: [ccp4bb] a simple question: how is redundancy measured?

2009-08-12 Thread Eleanor Dodson
I favour measuring a symmetry related reflection - it is more likely to 
have different systematic error.


But if you after Friedel differences there is some argument for measurng 
hkl and -h-k-l in the same orientation..


However high redundancy if you can achieve it always seems to me to give 
the best overall data set - high redundancy also gives you a statistical 
basis for rejecting outliers.

  Eleanor


Francis E Reyes wrote:
For a given reflection (h,k,l) how much does each situation increase 
the redundancy ? and which maximizes the ability to measure anomalous 
differences? (so assume we're separating friedel pairs here)



a) measuring the same reflection again

b) measuring a symmetry related reflection

c) both a+b

Thanks!

FR

-
Francis Reyes M.Sc.
215 UCB
University of Colorado at Boulder

gpg --keyserver pgp.mit.edu --recv-keys 67BA8D5D

8AE2 F2F4 90F7 9640 28BC  686F 78FD 6669 67BA 8D5D




[ccp4bb] a simple question: how is redundancy measured?

2009-08-11 Thread Francis E Reyes
For a given reflection (h,k,l) how much does each situation increase  
the redundancy ? and which maximizes the ability to measure anomalous  
differences? (so assume we're separating friedel pairs here)



a) measuring the same reflection again

b) measuring a symmetry related reflection

c) both a+b

Thanks!

FR

-
Francis Reyes M.Sc.
215 UCB
University of Colorado at Boulder

gpg --keyserver pgp.mit.edu --recv-keys 67BA8D5D

8AE2 F2F4 90F7 9640 28BC  686F 78FD 6669 67BA 8D5D