RE: Modeling with insufficient data

From: "Diane R Mould" drmould@attglobal.net Subject: RE: [NMusers] Modeling with insufficient data Date: Tue, October 26, 2004 6:59 am Hi Hyeong-Seok how are things going? that's going to be some awful run time, but its quite do-able. what I would suggest you do before modeling them simultaneously is to model them separately to get estimates of the volumes and clearances of each. then begin adding things piecewise. so model parent and first stage metabolites (possibly one at a time given the likely run times) set them up as each having its own compartment. so parent might be compartments one and two (if its oral and 1 comp pk) then metabolite 1 is compartment 3 and metabolite 2 is compartment 4 there is no need to initialize these compartments as there would be for an indirect type model so something like this $SUBS ADVAN6 TOL=3 $MODEL COMP=(gut) COMP=(cent defdose) COMP=(met1) COMP=(met2) COMP=(TRA) COMP=(met3) $PK "FIRST "COMMON/PRCOMG/IDUM1,IDUM2,IMAX,IDUM4,IDUM5 "INTEGER IDUM1,IDUM2,IMAX,IDUM4,IDUM5 "IMAX=50000000 then define the parameters and des $DES DADT(1)=-ka*a(1) dadt(2)=ka*a(1)-A(2)*K10-k23*a(2)-k24*a(2) dadt(3)=k23*a(2)-k20*a(3) dadt(4)=... when you are missing a piece, that's ok, but as Atul pointed out, you may have some difficulty identifying parameters. you may have to fix something. I hope that this is enough to get you started Diane _______________________________________________________