Dec 282017
 
FORTRAN source for nonlinear curve fitting. Requires editing of a routine for new curve to be fitted and recompiling. Old but timeless.
File NONLIN.ZIP from The Programmer’s Corner in
Category Miscellaneous Language Source Code
FORTRAN source for nonlinear curve fitting. Requires editing of a routine for new curve to be fitted and recompiling. Old but timeless.
File Name File Size Zip Size Zip Type
NONLIN.DOC 2337 950 deflated
NONLIN.FOR 45845 13491 deflated
NONLIN87.EXE 54246 31176 deflated
NONLINI 1152 178 deflated
NONLINO 7407 1590 deflated

Download File NONLIN.ZIP Here

Contents of the NONLIN.DOC file


NONLIN.FOR
----------



Written by: John Bolstad
Computer Science Department
Stanford University
July 1977


Modified for CP/M by: Norman C. Saunders
NJ Associates
Columbia, Md.
November 1983


Modified for DOS by: Ray Malitzke
3713 S.G. Mason Dr # 1304
Falls Church, VA, 2204
March 1993




NONLIN is weighted least-squares program designed to estimate
both the linear and non-linear parameters in a user-specified
function. Originally designed for large, mainframe computer
systems, NONLIN can, nonetheless, be implemented on a
PC system with a FORTRAN compiler.

NONLIN.FOR is composed of a main routine, 11 subroutines, and one
function. The subroutine ADA must be provided by the user in
order to specify for the program the form of the function to be
estimated. The programs are thoroughly commented and no further
documentation will be provided on the algorithm.

A sample version of ADA is provided with test data.
The results, in double precision, versus the expected results
are as follow for the test problem:

single precision expexted
result result
--------------------------------------------------------------
Linear parameter 1 0.3754 0.375
Linear parameter 2 1.9358 1.940
Linear parameter 3 -1.4647 -1.460

Non-linear parameter 1 0.01287 0.0129
Non-linear parameter 2 0.02212 0.0221
--------------------------------------------------------------

It is not known, in 1993, on what calculations the expected results
are based. The FORTRAN compiler used was from the MicroSoft,
version 5.0, with an 80287 coprocessor. Be aware that the EXE
sample file is also for the 8087 and will not execute without one.

For specific data and an equation to be fitted the ADA routine
and the rest of the program will have to recompiled.
This is the beauty of Public Domain source code.
Enjoy


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