Re: How does NONMEM $DES work?

From: "Nick Holford" n.holford@auckland.ac.nz Subject: Re: [NMusers] How does NONMEM $DES work? Date: Tue, December 21, 2004 8:58 pm Yaning, NONMEM uses the value of the data item, e.g. C, specified in the record for which a solution is sought e.g. ID TIME C DV 1 1 0 10 1 2 1 8 When NONMEM solves the DE system for the second record (TIME=2) it will assume that C is 1 throughout the interval from TIME=1 to TIME=2. If you are unable to find a model for C then you can interpolate a value using the T variable in $DES. There are several ways to do this but the most efficient might be to pre-compute the slope connecting each two values of C and use this to predict C at T. Add this slope to the data set and use it in $DES. e.g. ID TIME C DV SLOP 1 1 0 10 0 1 2 1 8 1 $DES CNOW=C-SLOP*T 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/