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MINIMIZE

FIT\MINIMIZE
Performs a fit of a theoretical profile in the R spectrum using initial
values specified by the command LINES. The profile is determined by the
METHOD command (GAUSS, SHELL or NH3 lines are currently implemented, and
a special method, CONTINUUM, may be used for continuum data).
MINIMIZE performs the fit only on the part of the spectrum selected by
SET MODE X. It also ignores the regions under the masks defined by SET
MASK.
If LINES is 0, an attempt to guess initial values for a single line is
done by computing the moments of the spectrum. A first minimisation is
performed using the Simplex technique; the results are improved and the
uncertainties computed using the Gradient technique. If MINIMIZE did not
converge, the errors quoted in the results are meaningless, and you
should use command ITERATE to try to do better.
For CONTINUUM method, although a linear baseline is fitted with the
gaussian, only the gaussian parameters are displayed. If the observa-
tion was made using beam-switching method and the reference beam appears
in the drifts, a two-component gauss fit is done using separation speci-
fied in the data.
The fitting results are saved in the R% variable, for e.g. reuse in pro-
cedures:
Method Structure
GAUSS R%HEAD%GAU%
SHELL R%HEAD%SHE%
NH3/HFS R%HEAD%HFS%
ABSORPTION R%HEAD%ABS%
CONTINUUM R%HEAD%POI%
See HELP SET VARIABLE for the detailed meaning of each component. For
example, the gaussian fit parameters can be found in:
Parameter Variable
Area R%HEAD%GAU%RESULT['(ILINE-1)*3+1']
Error(Area) R%HEAD%GAU%ERROR['(ILINE-1)*3+1']
Position R%HEAD%GAU%RESULT['(ILINE-1)*3+2']
Error(Position) R%HEAD%GAU%ERROR['(ILINE-1)*3+2']
Width R%HEAD%GAU%RESULT['(ILINE-1)*3+3']
Error(Width) R%HEAD%GAU%ERROR['(ILINE-1)*3+3']
where ILINE is the number of one of the fitted lines, between 1 and
R%HEAD%GAU%NLINE.

Gildas manager
2014-07-01