Hi Xinting, In a few rare cases, I've seen this happen if the model is approaching nonconvergence. In those cases, typically the RSE on one or more parameters will increase and the ratio of max to min eigenvalues will increase substantially. Are you seeing either of these?
Thanks, Bill On Aug 11, 2013, at 21:56, "Leonid Gibiansky" <lgibian...@quantpharm.com> wrote: Xinting, Try to start from the initial conditions of your "reduced" model but add that "reduced" ETA with the corresponding OMEGA equal to 0.01 or other small number. If the control stream code is correct, the objective function should decrease or retain the same value. Leonid -------------------------------------- Leonid Gibiansky, Ph.D. President, QuantPharm LLC web: www.quantpharm.com e-mail: LGibiansky at quantpharm.com tel: (301) 767 5566 On 8/10/2013 10:23 PM, Xinting Wang wrote: > Dear all, > > Does anyone witnessed such a phenomenon in NONMEM as when you reduced an > ETA, the OFV value, rather than increase, actually decreased? It's quite > against intuition, as individual estimation should be better than > population estimation in that particular parameter. Both models, whether > having this ETA, converged very well. > > Best > > -- > Xinting
