🚀 go-pugleaf

In <1jkb5nINN8qn@iskut.ucs.ubc.ca> holland@geop.ubc.ca (Stephen Holland) writes:


>Does anyone out there know where I might find a good public domain routine 
>for doing non-linear least-squares fitting WITHOUT derivative information.
>I'm looking for something along the lines of POWELL in Numerical Recipes or
>CHIFIT in Bevington.  ForTran source would be nice since my software is 
>writen in ForTran but i can translate from C if need be.

>thanks

>steve holland

I have used subroutine LMDIF from MINPACK (which you can get from netlib) and
NL2SOL (which you can also get from netlib, as part of TOMS) extensively and
for all my applications they work great. You can always do some kind of
difference approximation to the derivatives if you don't want to calculate them
explicitly (which is what those two subroutines do).

Those two routines are also very simple to program around also.

-- 
Walter Polkosnik                 
Physics Department         banana@panix.com        
Queens College, CUNY       {cmcl2,apple}!panix!banana