[Ifeffit] Re: I should be able to find this somewhere...
mamarcus at lbl.gov
Mon Jan 16 01:25:37 CST 2006
The background of this is that I'm running Artemis on Windows, and I get some odd things happening
when I select Display Residuals. The residual often shows as bigger than what's being fit. At first, I
thought that maybe it was being amplified by some factor in order to display better, but then I realized that
the behavior I'm seeing is inconsistent with that. For instance, the residual coincides with the data
at R greater than where the last fit path peters out. It's almost as if I'm seeing |fit+data| and not |fit-data|.
Matt Newville wrote:
> Maybe I missed an important part of the discussion, but that won't
> stop me from sticking my nose in...
> > > By what factor is the residual multiplied when plotted in Artemis? I can't
> > > find that figure quoted.
> > > mam
> > The residual is saved in k-space and Fourier transformed.
> ... which ought to be the same as taking the residual of chi(R).
> What's typically plotted (with Artemis and everywhere else) is
> |chi(R)|. When plotting the magnitude like this and selecting "show
> residual", the magnitude of the residual is shown:
> |chi_data(R)-chi_fit(R)|, not the invidiual differences of real and
> imaginary components.
> Ifeffit mailing list
> Ifeffit at millenia.cars.aps.anl.gov
More information about the Ifeffit