Re: [R] imposing constraints on the covariance matrix of random effects in lme4?

2007-07-13 Thread Douglas Bates
On 7/12/07, JVVerkuilen [EMAIL PROTECTED] wrote: Hello all, I am using lme4 to fit some mixed logistic regressions. I need to impose an identification constraint of the following form: (1sig12) (sig12 sig22) and have not figured out how to do it, i.e., sig11 = 1 but the rest of

[R] imposing constraints on the covariance matrix of random effects in lme4?

2007-07-12 Thread JVVerkuilen
Hello all, I am using lme4 to fit some mixed logistic regressions. I need to impose an identification constraint of the following form: (1sig12) (sig12 sig22) and have not figured out how to do it, i.e., sig11 = 1 but the rest of the parameters are free to vary. Is this possible and,