Re: separate parameter estimates

From:Nick Holford Subject: Re: [NMusers] separate parameter estimates Date:Thu, 13 Mar 2003 07:48:05 +1300 jm, If you do not assign a value to TVKA1 and TVKA2 then if the conditional DOSE statement is not executed the last value of the TV variable will be unchanged e.g. If DOSE is 1 then TVKA1 will be set to THETA(1) but if the next record has a DOSE of 2 then TVKA1 will remain with its previous value. This is a Fortran "feature" of static storage for variables. It is nothing directly to do with the code that NM-TRAN creates. Note that if the first record has DOSE of 2 then the value of TVKA1 is not explicitly defined. It will probably be zero because many compilers automatically zero all variables but you should not rely on this unless you are sure your compiler does this. TVKA1 and TVKA2 will never be affected by the POSTHOC (or FOCE) options. They are fixed effect not random variables. KA is a random variable (because it is affected by the random variable ETA(1) or ETA(2). In this particular case there is no point in assigning a value to TVKA1 or TVKA2. It would be simpler and IMHO clearer to write: ;This code assumes every record which does not have DOSE of 1 is a DOSE of 2 IF (DOSE.EQ.1) THEN KA=THETA(1)*EXP(ETA(1)) ELSE ; Assume DOSE is 2 by default KA=THETA(2)*EXP(ETA(2)) ENDIF If you use POSTHOC or FOCE then in your $TABLE record you could include DOSE and KA so that you can determine the individual estimate of KA according to dose group. 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/ _______________________________________________________