[phenixbb] Reflection file conversion

Ralf W. Grosse-Kunstleve rwgk at cci.lbl.gov
Tue Jan 19 10:06:47 PST 2010

> I use d*TREK to reduce my data and phenix.reflection_file_converter
> to import the data.  I seem to have had a bit of trouble generating
> the free R flags.  It seems that the cap for the max number of free
> R reflections takes precedence over the percentage, even when the
> percentage is given expressly on the command line.  I find myself
> setting the cap artificially high on the command line so that a full
> 10% is set aside.

Yes, that's what you need to do.

> I was taught to set aside 10% for the free R set, only going lower
> if setting aside the full 10% compromised completeness.  I'm just
> wondering what is the rationale for the numeric cap?  Am I making
> any error(s) with my methodology?

For the alpha/beta (or sigmaa) calculation you need a certain number
of reflections per resolution bin to get reasonable estimates. Say
you have 10 bins, 2000/10 = 200 is a sufficiently large sample per

I have to admit I'm uncertain about the pros and cons of setting
aside a larger number of reflections.


More information about the phenixbb mailing list