On Wed, 2012-05-23 at 10:02 -0500, Pete Meyer wrote:
> model and experimental errors do factor into calculation of a
> 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.
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