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562. AP: A General Fitting Program for Resolution of
Complex Profiles
by M. A. Raso, J. Tortajada, D. Escolar and F. Acción,
Departamento Química-Física(Espectroscopia),
Facultad CC. Químicas, Universidad Complutense, 28040
Madrid, España
AP is an interactive, conversational, general-purpose
program to fit experimental profiles to a set of
theoretical distribution functions. The functions
implemented are: Gaussian, Lorentzian, Gauss x Lorentz
and log-normal (asymmetric). Moreover, the program has
been developed in such a way as to be easily extended
to any other function.
Fitting is carried out by the least-squares procedure,
employing Newton's method in the search of the minimum
of squares of deviations. This method has been
modified with several optimization criteria to avoid
the nonconvergence problem.The algorithm and
intelligent handling of these criteria are described in
ref. 1.
Input instructions and operating procedures are
detailed in the documentation and in the COMMENT cards
within the program, especially in the main input
routines: LECESP, PAROPT and LECPAR. Sample decks and
associated output of two examples are provided.
The selected examples are two theoretical profiles
obtained as a sum of three Lorentzian and three log-
normal profiles, respectively. Fitting procedure of
these profiles illustrates the common use of
optimization criteria. The first example shows the
necessity and usefulness of the BLOCK OPTIMIZATION
criterion.The second explains the FIXED BAND
criterion.The way to estimate the initial
approximations of parameters is described in ref. 2.
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References:
1. M. A. Rasso, J. Tortajada, D. Escolar and F.
Acción, Comput. Chem., 11, 125 (1987).
2. J. Tortajada and F. Acción, J. Mol. Struct., 142,
263 (1986).
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FORTRAN 77 (VAX 11/750)
Lines of Code: 1865
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