[Ifeffit] delR and delE

[ritika.uppal at yale.edu]

Thanks, Bruce

Ritika
Quoting Bruce Ravel <ravel at phys.washington.edu>:

> On Thursday 14 October 2004 2:02 pm, ritika.uppal at yale.edu wrote:
> > I have another question. I have started from the beginning so that
> I
> > could follow all of Shelly's suggestions. I also looked up your
> start
> > guide for artemis fitting in which it says u can click the "fit
> > background" button if u see low R peaks. And then in the end it
> says
> > to click the "use previous background" button. but I can't seem
> to
> > find it. Could anyone direct me??
> 
> That page is rather out of date.  The procedure for dealing with
> the
> fitted background changed somewhat.  Here's the current situation:
> 
> 1.  Co-refine the background by selecting the fit background
> button.
> 2.  Play around with the value of Rmin to get a good background
>     co-refinement without undue correlations with the fitting
>     parameters.  These correlations are reported in the log file.
>     I would say that this procedure helps remove some of the
> mystery
>     as the "correct" value for Rbkg -- the cutoff in Fourier space
>     between background and data.  If the correlations are quite
> high,
>     that value is probably too high since you may be damaging the
> data
>     by allowing the spline too much freedom.
> 3.  In the Data menu is an option that says 'Save background
>     subtracted as chi(k)'.  This will write a file containing the
> data
>     with the fitted spline subtracted out to the project space. 
> You
>     will then be offered an opportunity to replace the data with
> the
>     background subtracted data.
> 4.  Choosing to import the background subtracted data will change
> the
>     data and unselect the "fit background" button.
> 5.  You can now continue along with your data analysis, using the
>     newly background-subtracted data.
> 6.  If you ever want to return to the non-background-subtracted
> data,
>     select "Project data -> Import project data" from the File
> menu.
>     This will open the file selection dialog in the folder where
> the
>     project's data is stored.  You will see the original data along
>     with the background-subtracted data and any other data you
> might
>     have (at some point) imported into your project.
> 
> HTH,
> B
> 
> -- 
>  Bruce Ravel  -----------------------------------
> ravel at phys.washington.edu
>  Code 6134, Building 3, Room 405
>  Naval Research Laboratory                          phone: (1) 202
> 767 2268
>  Washington DC 20375, USA                             fax: (1) 202
> 767 4642
> 
>  NRL Synchrotron Radiation Consortium (NRL-SRC)
>  Beamlines X11a, X11b, X23b
>  National Synchrotron Light Source
>  Brookhaven National Laboratory, Upton, NY 11973
> 
>  My homepage:    http://feff.phys.washington.edu/~ravel 
>  EXAFS software:
> http://feff.phys.washington.edu/~ravel/software/exafs/
> 
> _______________________________________________
> Ifeffit mailing list
> Ifeffit at millenia.cars.aps.anl.gov
> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
>