From: "Gastonguay, Marc" <firstname.lastname@example.org>
Subject: Caution with verbatim code/RE: Number of evaluations of differential equations
Date: Thu, 24 Aug 2000 15:41:11 -0400
Not too long ago, you indicated that you ran into the following error message with a differential equation model:
NUMERICAL DIFFICULTIES WITH INTEGRATION ROUTINE. MAXIMUM NO. OF EVALUATIONS OF DIFFERENTIAL EQUATIONS,100000, EXCEEDED
You also said that your attempt to increase the maximum number of evaluations with some verbatim code did not work (from your message):
" COMMON /PRCOMG/ IDUM1,IDUM2,IMAX,IDUM4,IDUM5
" INTEGER IDUM1,IDUM2,IMAX,IDUM4,IDUM5
I responded, in part, by incorrectly suggesting that there might be a hard-coded limit that was not affected by your verbatim code. In fact, Alison Boeckmann says that several users have implemented this code without a problem.
One possibility, though, is that the code has not been entered correctly in your control stream. The problem that other users have encountered when trying to implement this (and possibly other) verbatim code involves a single missed space.
If the line in A.(below) is mistakenly entered without a space between the quote and the C in COMMON (as in B. below), NMTRAN recognizes this line of verbatim code as a FORTRAN comment and the COMMON statement is ignored.
A. " COMMON /PRCOMG/ IDUM1,IDUM2,IMAX,IDUM4,IDUM5
B. "COMMON /PRCOMG/ IDUM1,IDUM2,IMAX,IDUM4,IDUM5
FYI: The original code cited in
<http://www.cognigencorp.com/nonmem/nm/98oct071998.html> is correct, but subsequent reiterations of this verbatim code to nmusers may have omitted this important space.
Hope this helps.
Marc R. Gastonguay, Ph.D
Manager, Pharmacometric R&D
7250 Parkway Drive, Suite 430
Hanover, MD 21076
Subject: Re: Caution with verbatim code/RE: Number of evaluations of differential equations
Date: Thu, 31 Aug 2000 16:21:08 +0000
many thanks for pointing out the issue with the single missed space. NONMEM now responds to changes in the specified number IMAX, such that I can now run my simulations without adding extra dummy samples "to fill in the gaps". I did not need to add too many more evaluations to get the system to run OK, just enough to get the PD function to turn a rather sharp corner just after the start of the drug administration (the response starts very quickly, reducing from a baseline value, leveling out close to zero, then recovering).
Best regards, Phil.