Re: [R] nls() and "singular grandient"

From: Spencer Graves <>
Date: Wed 23 Mar 2005 - 02:04:07 EST

      Many people could help you, but the question is too general. In brief, it means that the algorithm has found a place where the (estimated?) matrix of first or second partial derivatives is of reduced rank, and it refuses to do more. For such problems, I often use "optim".

      If you need more specifics, PLEASE do read the posting guide! "", prepare a very simple example of what you get, and submit that to this list. Many people find answers to their questions in the process of preparing a post following this guide, and those that don't, I believe, are more likely to get more informative replies.

      spencer graves

Guillaume STORCHI wrote:

>I have a problem with nls() when I want to fit a model with more than two
>parameters to be fitted which are written as start=list(a1=,a2=,a3=,...).
>Everytime, it displays:'error... singular gradient'
>it's a real pain!!!
>Hope sb knows something about this
> mailing list
>PLEASE do read the posting guide!
> mailing list PLEASE do read the posting guide! Received on Wed Mar 23 02:10:04 2005

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