NonlinearRegress fitfail error
- To: mathgroup at smc.vnet.net
- Subject: [mg89333] NonlinearRegress fitfail error
- From: Meaghan <FreeCaptive6914 at gmail.com>
- Date: Fri, 6 Jun 2008 06:46:06 -0400 (EDT)
I'm updating an old program to Mathematica 6. Here's the problem
code:
Needs["NonlinearRegression`"]
msoln = BestFitParameters /.
NonlinearRegress[part1, a2*(Exp[b2*x] - 1) + c2*x, startpoints, x,
AccuracyGoal -> 5, PrecisionGoal -> 5, MaxIterations -> 500,
RegressionReport -> BestFitParameters]
where "part1" is a long list of data points.
I know this method of replacement was valid in 5.2, but here I get:
FindFit::nrlnum: The function value {0.+(-1.+2.71828^(0. b2)) a2+0.
c2,0.104632+(-1.+2.71828^(0.195816 b2)) a2+0.195816 c2,<<8>>,<<92>>}
is not a list of real numbers with dimensions {102} at {a,b,c} =
{0.0369002,0.32,0.158379}.
NonlinearRegress::fitfail: The fitting algorithm failed.
ReplaceAll::reps: "{msoln} is neither a list of replacement rules nor
a valid dispatch table, and so cannot be used for replacing."
Thank you for the help!