Re: Problems with an apparent compiler-senstive model

From: Nick Holford n.holford@auckland.ac.nz Subject: Re: [NMusers] Problems with an apparent compiler-senstive model Date: Sun, 30 Jul 2006 12:36:48 +1200 Max, You are a bit vague about the difference in results. In my limited experience of comparing df6 with df6.6 some years ago I recall that the actual OBJ would be very similar if not identical but there might be some small differences in the parameter estimates. Indeed in some cases NONMEM appears to toss a coin and decide the run was successful and in other cases it decides to terminate (usually with rounding errors). I and others have investigated the termination criteria used by NONMEM and have not found any consistent difference in parameter estimates between runs which NONMEM describes as 'successfull' and those which are described as 'terminated'. So I suggest you look at the parameter estimates and model performance criteria (e.g. predictive check) to decide if there are really any important differences between the results from the two compilers. Dont rely on the NONMEM message about minimization status. On a somewhat different note -- all the df compilers are now obsolete i.e. it is impossible to buy a license for them from Compaq/HP. You may wish to consider switching to an actively supported compiler e.g. Intel Visal Fortran or the GNU g95 compiler. 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/