[Chimera-users] estimaded standard deviation (sigma levels) for electron densities in volume viewer

[Thomas Goddard]

Hi Sabuj,

  Chimera currently has no capability to display standard deviation
values for volume data.  It would be useful if the volume viewer dialog
had an option to use sigma units.

  Could you tell me what crystallographers define "1 sigma" to be for
a density map?  Is it the root mean square density value over the entire
map?

  For now here is a Chimera tool to report mean, root mean square, and
standard deviation values for a volume data set.

	http://www.cgl.ucsf.edu/home/goddard/temp/volumestats.tar

This archive contains a directory VolumeStatistics that you put in
your Chimera distribution in

	chimera/share

or on the Mac in

	Chimera.app/Contents/Resources/share

Then when you start Chimera you will have a new menu entry

	Tools -> Volume Data -> Volume Statistics

that reports the values for the current volume viewer data set, printing
them in the Chimera reply log (menu entry Favorites / Reply Log).

	Tom