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Curve fitting

5 messages · Jeff Newmiller, Bernard McGarvey, John C Nash

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Any recommendations on an R package to fit data to a nonlinear model Y=f(x) with a single x and y variable? 

I want to be able to generate parameter uncertainty estimates and prediction uncertainties if possible.

Bernard
Sent from my iPhone so please excuse the spelling!"
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stats::nlm?
On April 5, 2020 11:53:10 AM PDT, Bernard Comcast <mcgarvey.bernard at comcast.net> wrote:

  
    
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err... stats::nls...
On April 5, 2020 12:14:15 PM PDT, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote:

  
    
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Thanks Jeff

Bernard
Sent from my iPhone so please excuse the spelling!"
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Generally nlsr package has better reliability in getting parameter estimates
because it tries to use automatic derivatives rather than a rather poor numerical
estimate, and also uses a Levenberg-Marquardt stabilization of the linearized
model. However, nls() can sometimes be a bit more flexible.

JN
On 2020-04-05 3:20 p.m., Jeff Newmiller wrote: