On Wed, 2012-05-23 at 10:02 -0500, Pete Meyer wrote:
> bviously
> model and experimental errors do factor into calculation of a
> 2mFo-DFc
> map - but is weight and structure factor calculation part of map
> calculation, or a distinct stage of data processing?
Oh, I see. Sure, when the map coefficients are already available, the
further calculation does need sigmas, or even Fo's/Fc's. I think the
practical question Fransisco asked comes to this:
If you have no SIGFP column in the input mtz-file, REFMAC will by
default fail (phenix probably won't - at least I've seen datasets where
all the sigmas were reset to 1.00 and it didn't change the output a
bit). So one naturally things that sigmas are needed/used in map
calculation. Again in practical terms, just remove the SIGFP from LABIN
and it works, because refmac can do it both ways.
Cheers,
Ed.
--
After much deep and profound brain things inside my head,
I have decided to thank you for bringing peace to our home.
Julian, King of Lemurs
