No subject

   The button labeled `Auto align' will apply a crude algorithm in an
   attempt to align the spectra in an automated manner.  The algorithm
   works by computing the difference spectra of the derivative spectra
   of the standard and the second data groups.  It optimizes an e0
   shift by minimizing this difference spectra.  While this seems to
   work pretty well, I am sure data can be found for which it will
   fail badly.

In my defense, it seems to behave exactly as I described it ;-)

I notice that I am performing the minimization of the difference
spectrum over the entire data range.  It occurs to me that it would
probably be rather more reliable if I restricted the minimization to
the near-edge region, say E0-50, E0+100.  If you could send me a
project file with data that autoalign poorly, I would be happy to take
a look.

I would also be willing to implement some other automated alignment
algorithm if I were to be convinced that it would be an improvement.
However, I think that the caveat that data could be found for which an
alignment algorithm fails will hold true for just about any one.

B


-- 
 Bruce Ravel  ----------------------------------- ravel at phys.washington.edu
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