On Tuesday 18 March 2003 12:41 pm, Matt Newville wrote:
At the end of the analysis, it's usually best to do a full fit (that is, with all parameters floating) to understand the correlations between variables. Subtracting off a shell makes that impossible, so whiile analyzing differences has definite advantages, it should be done with caution.
It is very difficult to subtract uncertainty.
A darn good point! B -- Bruce Ravel ----------------------------------- ravel@phys.washington.edu Code 6134, Building 3, Room 222 Naval Research Laboratory phone: (1) 202 767 5947 Washington DC 20375, USA fax: (1) 202 767 1697 NRL Synchrotron Radiation Consortium (NRL-SRC) Beamlines X11a, X11b, X23b, X24c, U4b National Synchrotron Light Source Brookhaven National Laboratory, Upton, NY 11973 My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/