[R] nlmrt problems - No confInt, NA StdErr, t-, or p-values

[J C Nash]

Note that the recently released package nlsr by Duncan Murdoch and I has a slight update in the functions nlxb() and 
nlfb() as well as a lot of features for symbolic derivative calculation.

JN

On 2017-03-21 06:57 AM, DANIEL PRECIADO wrote:
> Dear list,
>
> I want to use nlxb (package nlmrt) to fit different datasets to a gaussian, obtain parameters (including standard error, t-and p-value) and confidence intervals.
>
> nlxb generates the parameters, but very often results in NA standard error,t-and p-values. Furthermore, using confint() to obtain the confidence intervals generates a : Error in vcov.default(object) :   object does not have variance-covariance matrix" erro.
>
> Can someone indicate why is nlxb generating NAs (when nls has no problem with them) and how to obtain confidence intervals from an nlmrt object?
>
> Thanks
>
>
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