R-factors: Difference between revisions

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


=== Model quality indicators ===
=== Model quality indicators ===
* R and R_free: the formula is (someone with LaTex knowledge please don't hesitate!)
* R and R_free: the formula is (LaTex please )


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

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 to fill in the formula!)
  • 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 (LaTex please )

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