[R] how to set the starting value in lme

[Ben Bolker]

Daniel Kaschek <daniel.kaschek <at> physik.uni-freiburg.de> writes:

> 
> Hi Jia,
> 
> in order to test if the failing parameter estimation really has to do
> with wrong initial values, you could first simulate data with your mixed
> effects model. Just assume parameters, produce a data set with these
> parameters, add noise and look if you can estimate the parameters
> correctly with varying initial guesses.
> 

  PS.  Correlations between random effects close to 1.0
(or -1.0) are usually a sign of insufficient data.
Further questions along these lines should probably go
to the r-sig-mixed-models list ...