MINIMUM ZETA: Difference between revisions
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== How could I check if a low value of MINIMUM_ZETA is beneficial for my data reduction? == | == How could I check if a low value of MINIMUM_ZETA is beneficial for my data reduction? == | ||
It does not hurt to use a low value of MINIMUM_ZETA (e.g. 0.05) in INTEGRATE, because in CORRECT you may still choose | It does not hurt to use a low value of MINIMUM_ZETA (e.g. 0.05) in INTEGRATE, because in CORRECT you may still choose higher values (i.e. you don't then have to re-run INTEGRATE if you want to test a different value). | ||
Then, run CORRECT with higher values and | Then, run CORRECT with the low values and with higher values and compare the resulting completeness and R-factors. | ||
For a finer evaluation, you might want to inspect the | For a finer evaluation, you might want to inspect the plots called 'rf.pck' of [[XDSSTAT]] . | ||
== Examples == | == Examples == | ||
Revision as of 11:39, 9 November 2007
As always, the authoritative documentation is at http://www.mpimf-heidelberg.mpg.de/~kabsch/xds/html_doc/xds_parameters.html#MINIMUM_ZETA= !
What is MINIMUM_ZETA?
MINIMUM_ZETA is a parameter determining how close reflections may be to the 'blind region' of reciprocal space to still be integrated. On the detector, the blind region consists of two cones starting at the direct beam position, and extending into the spindle direction.
A high value (corresponding to a large blind region) is "safe" but produces lower completeness because more pixels of the detector are considered to be in the blind region. The default of 0.15 is on the safe side. I routinely use 0.1, and 0.05 turns out to still be good.
How could I check if a low value of MINIMUM_ZETA is beneficial for my data reduction?
It does not hurt to use a low value of MINIMUM_ZETA (e.g. 0.05) in INTEGRATE, because in CORRECT you may still choose higher values (i.e. you don't then have to re-run INTEGRATE if you want to test a different value).
Then, run CORRECT with the low values and with higher values and compare the resulting completeness and R-factors.
For a finer evaluation, you might want to inspect the plots called 'rf.pck' of XDSSTAT .