NonlinearFit
- To: mathgroup at yoda.physics.unc.edu
- Subject: NonlinearFit
- From: 4_DKEFFORD at fair1.fairfield.edu
- Date: 05 Mar 1993 14:17:31 -0500 (EST)
Hello everybody.
Thanks for all your responses- many of you suggested that I use the latest
version of NonlinearFit available as shareware. I git it running and was
able to get it to work for a parabolic and a linear fit with no problems.
However, when I try to do a double exponential fit, which is what I need to
do in the first place, I keep getting the following error:
NonlinearFit::baddata '1' is not a real matrix
I have really no idea why this happens- I'm simply using about 200 points
generated from a known double exponential, which I created as follows:
silicon=Table[{x,f[x]},{x,-50,450,5}]
where f[x_]=-.2*Exp[-.01*x]+.1*Exp[-.05*x]
Then I run the following:
NonlinearFit[silicon,a*Exp[-b*x]+c*Exp[-d*x],{a,b,c,d},x]
As far as I can see, I do not have any syntax errors or anything else that
springs to the imagination. Any ideas??
I can be reached at either:
4_dkefford at fair1.fairfield.edu or
dkefford at delphi.com
Thank for your time.
Dan Kefford