Hi George. It should be 2*(Delta k)*(Delta R), without the +2, but as a floating point number. That is, it is deliberately conservative. I believe the subtle difference you see (that is why the value is 27.06 instead of 27.5) must be due to rounding of the R values on to a discrete grid.
-Matt On Oct 10, 2011 9:35 AM, "George Sterbinsky" < georgesterbin...@u.northwestern.edu> wrote: > Hello, > > Since I haven't received a response to my previous question, I just wanted > to make sure I asked it clearly. To elaborate, I am attaching a log from > Athena. The log file lists: > > "Independent points = 27.057617188" > > If I attempt to reproduce this result using the equation in the feffit > document, I find > > Nidp = { [2*(kmax - kmin)*(Rmax-Rmin) / pi] + 2} = { [2*(14 - 0.5)*(4.2 - > 1.0) / pi] + 2} = 29.50197417, > > where I have used the k-range and R-range in the log file as kmax, kmin, > Rmax, and Rmin. > > Can someone explain to me why may calculation does not reproduce the number > given for "independent points" in the log fie? > > Thank you, > George > > On Fri, Oct 7, 2011 at 1:04 PM, George Sterbinsky < > georgesterbin...@u.northwestern.edu> wrote: > >> Hello, >> >> I am wondering what values Artemis/feffit use for kmax and kmin when >> calculating the number of independent points (Nidp) for a fit done in >> R-space, where according the feffit document, Nidp = { [2*(kmax - >> kmin)*(Rmax-Rmin) / pi] + 2}, and kmax and kmin define the fitting range. I >> have tried using the Fourier transform range for kmax and kmin, but this >> does not give agreement with the value of Nidp reported by Artermis. >> >> Thank you, >> George >> > > > _______________________________________________ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > >
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