Hi Michael, This seems like a question that others might have, so I hope it's OK that I'm sending this reply to the ifeffit mailing list too. On Thu, 23 May 2002, Michael Green wrote:

I can't figure out how to use a standard for background removal in G.I.FEFFIT or IFEFFIT. Is there a way to do this? Table 4 of the Refman lists a chi_std data type, but I didn't find any mention of it anywhere else.

Yes. In ifeffit, it would go like this: #### # background-removal using known chi(k) data read_data(file= data.xmu, label= 'energy xmu', group= dat) read_data(file= standard.chi, label= 'k chi ', group= std) # without standard spline(energy= dat.energy, xmu= dat.xmu, kweight=1,rbkg=1) # with standard spline(energy= dat.energy, xmu= dat.xmu, kweight=1,rbkg=1, k_std=std.k, chi_std = std.chi) #### That is, you read in the spectra for the standard, and use it's "k" and "chi" arrays for "k_std" and "chi_std". Hope that helps, --Matt