CCP14
    Tutorials and Examples
    Peak Fitting using Xfit-Koalariet (Coelho and Cheary) for Win95/NT
    Why won't Xfit fit xy column data!?
    The CCP14 Homepage is at http://www.ccp14.ac.uk
    
[The reference to use for XFIT or FOURYA in any resulting publications is:
Cheary, R. W. & Coelho, A. A. (1996). Programs XFIT and FOURYA, deposited in CCP14 Powder Diffraction Library, 
Engineering and Physical Sciences Research Council, Daresbury Laboratory, Warrington, England. 
(http://www.ccp14.ac.uk/tutorial/xfit-95/xfit.htm)]
Extracted from the Rietveld Mailing list
From: L.M.D.Cranswick@dl.ac.uk (L. Cranswick)
Subject: Re: Koalariet software
To: rietveld_l@ill.fr
Date: Sat, 28 Nov 1998 16:11:54 +0000 (GMT)
Reply-To: RIETVELD_L Distribution List 
> We have installed the may 1998 version of Xfit-Koalariet  for Win95.
> After installing we run several of the samples from your tutorial and they
> worked fine. Yet we loaded a .xy file of our own data. The Xray powder
> pattren was correctly displayed in the coresponding window. Yet when
> we try to select diffraction peaks with the ins/del peak tool the
> programs does not allow us to do so and instead an error window with the
> message "cannot insert peak into this file".
> Could you please help us with this problem.
This is a limitation with XFIT in that it can only handle constant
step data when fitting - but can display non-constant step .xy data.
XFIT assumes .xy data is non-constant step data.  Can you convert
the .xy data into another format such as column CPI, XDD or DAT?
Examples of data files are with the distribution or at:
   http://www.se.iucr.org/iucr-top/comm/cpd/QARR/data-kit.htm
   http://www.us.iucr.org/iucr-top/comm/cpd/QARR/data-kit.htm
   http://www.ch.iucr.org/iucr-top/comm/cpd/QARR/data-kit.htm
   http://www.iucr.org/iucr-top/comm/cpd/QARR/data-kit.htm
-- 
Lachlan M. D. Cranswick
Collaborative Computational Project No 14 (CCP14)
    for Single Crystal and Powder Diffraction
Daresbury Laboratory, Warrington, WA4 4AD U.K
Tel: +44-1925-603703  Fax: +44-1925-603124  
E-mail: l.cranswick@dl.ac.uk  Ext: 3703  Room C14
NEW CCP14 Web Domain (Under heavy construction):
                           http://www.ccp14.ac.uk