Hi Li,
before you increase the number of maximal evaluations you should try the
ADVAN8 or ADVAN13 solvers. It is typically a sign for a stiff differential
equation if a high number of steps is needed to meet the specified
integration tolerance.
ADVAN8 is using more complicated numerical methods to solve the ODE. For a
non-stiff ODE those additional efforts lead to longer run times with no
additional benefits. For a stiff ODE these efforts lead to a quicker
solution.
ADVAN13 is a hybrid version between stiff and non-stiff solver which tries
to determine automatically what method is most adapted.
Hope that help
Sebastian
Sebastian Ueckert, MSc, PhD student
-----------------------------------------------
Pharmacometrics Research Group,
Department of Pharmaceutical Biosciences,
Uppsala University
-----------------------------------------------
P.O. Box 591
SE-751 24 Uppsala
Sweden
-----------------------------------------------
sebastian.ueckert
-----------------------------------------------
Work: +46-(0)18-471 4437
On Wed, Jun 22, 2011 at 10:17 PM, Li Li <lili.uf2009
> Hi,
>
> I am using ADVAN 6 to do some PKPD modeling and got this error message:
> NUMERICAL DIFFICULTIES WITH INTEGRATION
> ROUTINE.
>
> MAXIMUM NO. OF EVALUATIONS OF DIFFERENTIAL EQUATIONS, 1000000,
> EXCEEDED.
>
> I know in NONMEM 6 you may use following code to increase maximum number of
> integration of differential equation:
> "FIRST
> " COMMON /PRCOMG/ IDUM1,IDUM2,IMAX,IDUM4,IDUM5
> " INTEGER IDUM1,IDUM2,IMAX,IDUM4,IDUM5
> " IMAX=100000000
> But in NONMEM 7 it gave error message:
> (WARNING 113) VERBATIM CODE CONTAINS "COMMON". IF THIS IS NOT A
> USER-DEFINED COMMON, IT SHOULD BE REPLACED BY THE APPROPRIATE MODULE.
> CREATING MUMODEL ROUTINE...
>
> Thus, how can I increase maximum number of integration of differential
> equation in NONMEM 7?
>
> Thank you.
>
> lili
>
How to Increase Maximum NO. of Evaluations of Differential Equation in NONMEM 7
Li Li,
In addition you may try ADVAN9, though ADVAN13 may have advantages over ADVAN9.
Matt.
Quoted reply history
-----Original Message-----
From: owner-nmusers
Behalf Of Luann Phillips
Sent: Wednesday, June 22, 2011 4:44 PM
To: Li Li
Cc: nmusers
Subject: Re: [NMusers] How to Increase Maximum NO. of Evaluations of Differential Equation in NONMEM 7
Li Li,
If this is the model that you have described previously, you may want to
try ADVAN8 or ADVAN13. With the cusps that the on/off nature of your
rate constant a stiff diff. eq. solver may perform better.
best regards,
Luann Phillips
Director PK/PD
Cognigen Corporation
Li Li wrote:
> Hi,
>
> I am using ADVAN 6 to do some PKPD modeling and got this error message:
> NUMERICAL DIFFICULTIES WITH INTEGRATION
> ROUTINE.
>
> MAXIMUM NO. OF EVALUATIONS OF DIFFERENTIAL EQUATIONS, 1000000,
> EXCEEDED.
>
> I know in NONMEM 6 you may use following code to increase maximum number
> of integration of differential equation:
> "FIRST
> " COMMON /PRCOMG/ IDUM1,IDUM2,IMAX,IDUM4,IDUM5
> " INTEGER IDUM1,IDUM2,IMAX,IDUM4,IDUM5
> " IMAX0000000
> But in NONMEM 7 it gave error message:
> (WARNING 113) VERBATIM CODE CONTAINS "COMMON". IF THIS IS NOT A
> USER-DEFINED COMMON, IT SHOULD BE REPLACED BY THE APPROPRIATE MODULE.
> CREATING MUMODEL ROUTINE...
>
> Thus, how can I increase maximum number of integration of differential
> equation in NONMEM 7?
>
> Thank you.
>
> lili
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