Skya, Seeing an example Athena file would help, but my guess is that one or more of your standards are being rejected by the fit (i.e. near zero), when this occurs the LCF routine can finish without the sum forced equal to zero. If this is the case you can just rerun the fit excluding the standard that is near zero and the sum should now equal 1. Dave _________________________________ David Barton, -----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Skya Fawcett Sent: Monday, September 17, 2007 3:07 PM To: ifeffit@millenia.cars.aps.anl.gov Subject: [Ifeffit] Linear Combination Fitting in Athena I'm trying to do linear combination fitting on a number of samples, and its working well for the most part, with 4 exceptions. There are 4 samples, of 22, that I can't get to sum to 1, despite the fact that I have "sum to 1" checked off before fitting. I've tried reprocessing the data, and tried reinstalling Athena with no luck. Any ideas? Skya Fawcett PhD Candidate Department of Geological Sciences and Geological Engineering Queen's University, Kingston, Canada _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit