RE: Non-physiological parameters at lowest OBJ
From: Chuanpu Hu <chuanpu.2.hu@gsk.com>
Subject: RE: [NMusers] Non-physiological parameters at lowest OBJ
Date: 8/6/2003 11:32 AM
Leonid,
I do notthat there is a universally better way. Although there may be desirable reasons
to have a model having independent KA and KE, I doubt that is necessary or theoretically
sound for the following reason. The correlation between KA and KE is not all bad, because
when they are close, the constraint KA>KE implies a strong correlation. Ideally, this
correlation should become small when the difference gets larger, which is indeed how the model
...
KA=KE+THETA(3)*EXP(ETA(3))
behaves like (from a formula in my 1998 intermediate NONMEM workshop handout). That is, what
Vladimir (and the NONMEM workshop) proposed does have good properties, and is easy to implement.
Chuanpu