search for: cs1grp

Displaying 1 result from an estimated 1 matches for "cs1grp".

Did you mean: chgrp
2004 Sep 18
0
Pharmacokinetics using R
...ge problem I am running into and I hope to get some assistance from the group. The following code works fine in S-Plus (Population estimates and MAP estimates look reasonable ). cs.fit<-nlme ( CONC~phenoModel(CID,TIME, DOSE, lCl, lV), fixed = lCl+lV ~1, random = pdDiag(lCl+lV ~1), data = cs1grp, start = c(-5, 0), na.action=na.include, naPattern = ~ !is.na(CONC) ) But if I run the same problem in R, I get the following error: "Error in chol((value + t(value))/2) : the leading minor of order 1 is not positive definite" These are simulated data with a...