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652. ABACUS: Interactive Program for Nonlinear Regression
Analysis
by William Damert, U.S. Department of Agriculture, 600
E. Mermaid Lane, Philadelphia, Pennsylvania 19118
ABACUS is a program for performing nonlinear regression
analysis using the Gauss-Newton iteration algorithm on
x-y data input from a file. The program is written for
VAX/VMS FORTRAN-77 and is distributed with a function
for fitting any number of GAUSSIAN peaks and with
several other common functions. It is designed so the
user may easily replace the functions provided with
other mathematical formulas containing parameters to be
determined.
The program is command driven, with commands that allow
the user to select the function and options, change
parameters, draw a graph of the data points overlaid
with the current function, perform iterations, allow
parameters to vary or force them to stay fixed in
value, set bounds on parameter values, and print
reports.
The program has dimensions set to allow variation of up
to 100 parameters and executes quickly enough to be
used interactively using a GAUSSIAN function or other
easily evaluated function on problems of that size.
The graphics calls adhere to the GKS standard, and
users may link the program with their own GKS libraries
for device independent graphics. In addition, the
program includes graphics drivers for a Tektronix
terminal. Documentation for users and documentation
for persons wishing to modify the program or to add new
functions are provided.
Lines of Code: 5502
FORTRAN 77 (VAX)
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