[R] Nonlinear mixed effects model

[Cam]

In nonlinear mixed effects models, SAS doesn't allow for free manipulation of
the covariance matrix (you can only specify a "type", and our "type" doesn't
exist). Can R accomplish this? For example:

Parameters:
B1= Beta 1i
B2= Beta 2i
G1= Gamma i


y = B1 -(B1 - B2) exp { - G1 time} + e

the covariance matrix for 
(B1         [( covB1?     covB1B2   covB1G1
 B2    ~      covB2B1    covB2?     covB2G1
 G1)           covG1B1   covG1B2   covG1?   )]

**If we want to specify covG1B1 and make everything else 0's, for example,
what would the code look like? 



Thanks for your time.
-- 
View this message in context: http://www.nabble.com/Nonlinear-mixed-effects-model-tf2397889.html#a6686679
Sent from the R help mailing list archive at Nabble.com.