[R-sig-ME] lack of convergence

[Douglas Bates]

On Fri, Jul 8, 2011 at 6:20 AM, Mike Gibson <megalops31 at hotmail.com> wrote:

> I already ran a mixed model and got convergence.  I have 700 data points.  Now, I am running a new mixed model that adds the ARMA (corARMA) covariance pattern.  I keep getting an error message telling me that the model did not reach convergence.  I already tried reducing my tolerance to 1e-1 and increased the number of iterations to 7,000.  Still, I am not having any luck.

> Any suggestions to get my model to work properly so I can get my parameter estimates?  I pasted my covariance code below.

> LVB2.nlme<-update(LVB.nlme, corr=corARMA(p=1, q=1),
> control=nlmeControl(maxIter=6000, tolerance=1e-1, msVerbose=TRUE))

Do you see any patterns in the verbose output indicating that the
parameter estimates are getting stalled somewhere?