[Ifeffit] plot multiplier in Athena

Bruce Ravel bravel at bnl.gov
Mon Jan 5 16:39:05 CST 2009


On Sunday 04 January 2009 05:00:56 am you wrote:
> Dear Bruce,
>
> Since the 2 or 3 latest athena versions, I have noticed a somewhat
> strange behavior of the 'plot multiplier' command in athena.  I'm 
> using the latest horae and iffefit releases on linux (Madriva 2007) and  
> windows (XP, SP3).  
>
> The plot multiplier works for  chi and fourier-transformed spectra, but
> fails for xanes and xmu spectra: changing the plot multiplier to a value
> different from 1 makes  no  effect of the last two types of spectra.
> In contrast,  'y-axis offset' command works for all types of  spectra.
>
> Personally, I found the possibility to multiply xanes spectra extremely
> convenient (as far as I remember, it worked in older than 2006  versions
> of athena....), for example for quick comparison and superposition 
> short-energy range  XANES spectra for which the athena energy normalisation 
> procedures do not work perfectly in some cases.

Gleb,

At some point I decided that the plot multiplier should only apply to 
oscillatory-like functions and not to step-like functions.  That is, you can 
scale up the derivative of mu(E), but not mu(E) or norm(E).  To the best of 
my memory, it has been like that for many years.

Thinking about it today, that decision does not really make a lot of sense.  I 
cannot see a reason why Athena should not behave the way you suggest, so it 
will do so in the next release.

Regards,
B



-- 

 Bruce Ravel  ------------------------------------ bravel at bnl.gov

 National Institute of Standards and Technology
 Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2
 Building 535A
 Upton NY, 11973

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