[Ifeffit] Athena and "norm" file groups

[Anatoly Frenkel]

I would try to rename .norm by .xmu and see if it will be able to do what
you want.
I would still be cautious doing it because .norm means that the raw data
was already altered (pre-edge function was subtrated and slope changed).
Doing anything like that is possible but not wise because it is not
guaranteed that you would obtain the same result as when you start from the
raw data directly.

For example, suppose "norm1" is normalization operation with one set of
parameters, and "norm2" - with another. Xmu is the raw absorption
coefficient data (obtained from the ratio of detector signals).
It is not likely that norm2 (xmu) will give the same results as
norm2(norm1(xmu)), although the differences may be small. That is the
reason, I think, Athena does not allow any ex post factum normalization to
the normalized data.

Anatoly Frenkel
Stony Brook University

On Oct 15, 2016 4:10 PM, "Mike Massey" <mmassey at gmail.com> wrote:

> Hi everyone,
>
>
> Apologies if this has been covered before, I'm just getting around to
> upgrading to Demeter. I have a bunch of old project files with a mishmash
> of data from different sources, and I'm having trouble getting them to work
> fully with the new software.
>
> Any group with a data type of "xmu" (energy space) seems to work as
> expected, but any group with a data type of "norm" (normalized data)
> doesn't seem to work properly when it comes to spline or post-edge
> background subtraction (which is handy if I want to do LCF, for example).
> Is this a bug or a feature? Has anybody yet developed a workaround?
>
> Any thoughts or advice would be greatly appreciated. The ultimate
> workaround is to use different data, but I'd like to use existing projects
> if possible (saves a lot of time and brain damage).
>
>
> Cheers, and thanks!
>
>
> Mike
>
>
>
>
>
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