Dear All (& Franz), Use FXYE format. The positions given actually override those that would be calculated from the average stepwidth given on the "BANK" record where it matters. This scheme is only valid where the goniometer doesn't give truly uniform steps but "jitters" about some average. Most important, one can not "skip" regions or change step width dramatically (apart from the jitter) within the scan. In more detail - the FXYE positions are used to determine the positions of each profile point in the Rietveld refinement relative to neighboring reflection positions in the peak shape calculations. That is where they must be precisely known. The average step size is only used to compute profile bin numbers for, e.g., the cutoffs for reflection widths and other places where the actual position doesn't matter that much. Hope that helps, Bob Von Dreele
R.B. Von Dreele IPNS Division Argonne National Laboratory Argonne, IL 60439-4814 -----Original Message----- From: Franz Werner [mailto:[EMAIL PROTECTED] Sent: Friday, November 03, 2006 9:45 AM To: rietveld_l@ill.fr Subject: GSAS: Data with uneven stepwidth Dear All Does anyone know how to treat CW data files with uneven stepwidths? Although there are the "FXY" and "FXYE" TYPEs where one sets the positions explicitly, the BINTYP (where there is always sort of a stepwidth) overrides it. Is there a kludge to persuade GSAS to use the positions as-input? Thank you for your comments. Franz Werner Technische Universität Wien Austria -- GMX DSL-Flatrate 0,- Euro* - Überall, wo DSL verfügbar ist! NEU: Jetzt bis zu 16.000 kBit/s! http://www.gmx.net/de/go/dsl
