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ACCUMULATE

LAS\ACCUMULATE [/RESAMPLE [NX Xref Xval Xinc Unit]] [/NOCHECK Arg1
... ArgN]] [/WEIGHT TIME|SIGMA|EQUAL|ASSOCIATED]
ACCUMULATE is used to add a pair of spectra together. The T spectrum is
added to the R spectrum using the specified (/WEIGHT) or current (SET
WEIGHT) weighting function (see HELP SET WEIGHT for details). To stack
more than 2 spectra, you should build an index and AVERAGE it in a sin-
gle step instead (this will prevent cumulative resamplings, respect the
respective weights, and preserve at best the noise properties).
On return R contains the sum spectrum, and T the observation previously
in R. If /WEIGHT or SET WEIGHT is ASSOCIATED (see HELP SET WEIGHT for
details), the weight array of the sum spectrum is saved in the associat-
ed array named W.
The spectra are stacked channel by channel by default, if possible. Else
the option /RESAMPLE must be invoked (see subtopic for details).
For EQUAL weights, ACCUMULATE computes the sum of the two spectra, al-
lowing addition of an ensemble of spectra after division by the total
number of spectra. For other weightings, ACCUMULATE computes the average
of the two spectra.
ACCUMULATE also works on Continuum drift. The alignement may be Channel
or Position in this case.

**Subsections**

Gildas manager
2018-05-18