On Thursday, 13 February 2014 04:46:51 AM Keller, Jacob wrote: > Dear Crystallographers, > > Where can I find the definition of the R vs batch reported in scaling? > Specifically I am wondering whether it is cumulative (each new frame versus > all previous ones pooled together) or something else,
Something else. It is calculated by comparing the scaled I's from the current batch to symmetry equivalents of those same Bragg reflections in all other batches being scaled. > and also how this metric can have any meaning on early frames You can't do this kind of scaling until you have all the frames (batches). > when one has measured each reflection only once (in p1, this would be 180 > degrees). If you have only one measurement of each hkl you're going to have a hard time calculating merging R factors :-) If your detector is centered on the beam (2theta = 0) then 180 degrees will get you 2 measurements of each reflection. That's disregarding breakage of Friedel's Law by anomalous scattering and also the possible unusability of reflections near the rotation axis. > I am wondering about its efficacy as a radiation-damage metric. > > JPK > > ******************************************* > Jacob Pearson Keller, PhD > Looger Lab/HHMI Janelia Farms Research Campus > 19700 Helix Dr, Ashburn, VA 20147 > email: kell...@janelia.hhmi.org > *******************************************
