R-factors: Difference between revisions

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(New page: Historically, R-factors were introduced by ... == Definitions == === Data quality indicators === * R_sym and R_merge: the formula is (someone with LaTex knowledge please don't hesitate!)...)
 
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== what kind of problems exist with these indicators? ==
== what kind of problems exist with these indicators? ==
- (R_sym/R_merge) should not be used, R_meas should be used instead (explain why ?)
- (R_sym/R_merge) should not be used, R_meas should be used instead (explain why ?)
- R/R_free and NCS: reflections in work and test set are not independant
- R/R_free and NCS: reflections in work and test set are not independant

Revision as of 08:36, 9 February 2008

Historically, R-factors were introduced by ...

Definitions

Data quality indicators

  • R_sym and R_merge: the formula is (someone with LaTex knowledge please don't hesitate!)
  • Redundancy-independant version of the above: R_meas
  • measuring quality of averaged intensities/amplitudes: R_p.i.m./R_mrgd-F

Model quality indicators

  • R and R_free: the formula is (someone with LaTex knowledge please don't hesitate!)

what do R-factors try to measure, and how to interpret their values?

  • relative deviation of

what kind of problems exist with these indicators?

- (R_sym/R_merge) should not be used, R_meas should be used instead (explain why ?)

- R/R_free and NCS: reflections in work and test set are not independant