Hi Matt, I have some questions about a subtle detail in ifeffit. It is possible to make a def parameter which is path sensitive in the sense that it will evaluate differently for different paths. Any def parameter which includes reff, eins(), or debye() in its math expression will be that way. Here is a simple, if slightly silly, example: def rrr = reff/10 path(1, feff=feff0001.dat, dr=rrr) path(2, feff=feff0002.dat, dr=rrr) Then show rrr will report 1/10 the R_eff of the *second* path. So here are my questions: 1. Are all def parameters reevaluated every time a new path is evaluated? Or only if the path uses the def parameter in one of its math expressions? (I think the answer is the former.) 2. Is it possible to ask ifeffit which def parameters are path sensitive? Of course, I can scan the def parameters at the level of perl to see if any of them obviously are, but ifeffit might already know that. 3. If you do show ss the value is the value of the last path evaluated. Doing show @path N show ss will indeed display the value of the def parameter appropriate to the Nth path. Is there another way of forcing ss to be evaluated appropriate to a desired path? Thanks, 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/