Re: Different population estimates

From: Nick Holford n.holford@auckland.ac.nz Subject: Re: [NMusers] Different population estimates Date: 11/17/2003 2:53 PM Toufigh, You said the differences in PRED at the same dose for different subjects were small. This might be explained by numerical errors produced by the DE solver. The path taken by the solver may be different if the output times differ from subject to subject. You could try changing TOL and/or try using ADVAN9 to see if this altered the discrepancy. You might also consider changing the $DES code to make it computationally more efficient and IMHO easier to read. There is no need to repeatedly divide A(1)/V1 and A(2)/V2 when it can be done once. $DES CON1=A(1)/V1 CON2=A(2)/V2 DADT(1)=CON2*Q - CON1*(VM/(KM+CON1) + Q) DADT(2)=Q*(CON1-CON2) Nick -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x86730 fax:373-7556 http://www.health.auckland.ac.nz/pharmacology/staff/nholford/