Re: [R] specifying random effects covariance structure in nlme

I haven't played with this for a decade or so, but I believe you can do something with pdBlocked(). Possibly ask over on R-sig-ME as this quickly gets beyond the R-help level. (Also, you are aware that it is not about what you want to estimate, but whether you believe the correlations are

[R] specifying random effects covariance structure in nlme

Hi I'm trying to fit a mixed effects exponential decay model, in which I have random effects for the initial value (init), the asymptote (asymp), and the rate (rate). The catch is that I'd also like to estimate the correlation between init and asymp, but not between init and rate, or asymp