[R] gnlsControl

[Dieter Menne]

Daniel Coleman <coleman.daniel <at> gene.com> writes:

> 
> When I run gnls I get the error:
> 
> Error in nls(y ~ cbind(1, 1/(1 + exp((xmid - x)/exp(lscal)))), data = xy,  :
> 
>         step factor 0.000488281 reduced below 'minFactor' of 0.000976563
> 
> My first thought was to decrease minFactor but gnlsControl does not contain
> minFactor nor nlsMinFactor (see below).  It does however contain nlsMaxIter
> and nlsTol which I assume are the analogs of maxiter and tol in nls.control.
> I would be happy to hear from anyone who has an idea on what parameters in
> gnlsControl to change to get convergence.  

Try nlsTol with a large value, e.g. 0.3. If I am really desparate, I put the
gnls in a try() structure, halving nlsTol until it fails, and take the last
successful. 

Dieter