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RE: NONMEM message

From: Higashimori, Mitsuo <Mitsuo.Higashimori>
Date: Thu, 13 Nov 2008 14:26:59 +0900

Dear Nick,

Thank you for your advice.
In my case, covariance matrix also was displayed without any problem. =
So, I could check whether covariance matrix is reasonable or not, but it =
was difficult to interpret it for me. Therefore, I wanted to know if =
this message is important. In addition, I mused if such a result should =
be excluded from listing and summarizing the result files after =
bootstrap.

Best regards,
Mitsuo


> -----Original Message-----
> From: owner-nmusers
> [mailto:owner-nmusers
> Sent: Thursday, November 13, 2008 1:58 PM
> To: nmusers
> Subject: Re: [NMusers] NONMEM message
>
>
> Mitsuo,
>
> This is a special kind of NONMEM error message:
>
> MINIMIZATION SUCCESSFUL
> HOWEVER, PROBLEMS OCCURRED WITH THE MINIMIZATION.
> REGARD THE RESULTS OF THE ESTIMATION STEP CAREFULLY, AND
> ACCEPT THEM ONLY
> AFTER CHECKING THAT THE COVARIANCE STEP PRODUCES REASONABLE OUTPUT.
>
> because the message itself seems to be an error.
>
> Whenever I see this message the covariance step does not run
> therefore I
> cannot decide if the covariance step produces reasonable output. I
> therefore ignore this message after the word SUCCESSFUL.
>
> The numerical oddities in NONMEM are well known so I am not surprised
> that raising women to a power make them have a different
> influence from
> distinguishing them explicitly from men. The power approach is
> computationally much less efficient than a conditional
> expression so I
> never use it if I can avoid it.
>
> Nick
>
> Higashimori, Mitsuo wrote:
> > Dear all,
> >
> > I have a following error(?) massage on a poplation analysis
> using NONMEM VI.
> >
> > 0MINIMIZATION SUCCESSFUL
> > HOWEVER, PROBLEMS OCCURRED WITH THE MINIMIZATION.
> > REGARD THE RESULTS OF THE ESTIMATION STEP CAREFULLY, AND
> ACCEPT THEM ONLY
> > AFTER CHECKING THAT THE COVARIANCE STEP PRODUCES REASONABLE OUTPUT.
> >
> > I found it when I described a control stream to assess sex
> difference on oral clearance as shown in below,
> >
> > TVCL = THETA(1) * THETA(2) ** SEX
> > where SEX=0 for male and SEX=1 for female.
> >
> > This message was displayed without any error message. It
> was not dissapeared even though I changed the initial
> parameters. However, it was solved when I changed the model
> definition. For example,
> >
> > TVCL = THETA(1)
> > IF (SEX.EQ.1) TVCL = THETA(2)
> >
> > Could you please let me know some details regarding the
> message. Especially, I'd like to know
> >
> > 1. What impact does this error message give the analysis result?
> > 2. Why does it depend on the model definition?
> >
> > Thanks,
> >
> > _/ _/ _/ Mitsuo Higashimori, Ph.D.
> > _/ _/ _/ Pharmacokinetic Group, Early Phase Development Department
> > _/ _/ _/ Clinical Division, Research & Development
> > _/ _/ _/ AstraZeneca K.K.
> > _/ _/ _/ E-mail: Mitsuo.Higashimori
> >
> >
> >
> >
>
> --
> Nick Holford, Dept Pharmacology & Clinical Pharmacology
> University of Auckland, 85 Park Rd, Private Bag 92019,
> Auckland, New Zealand
> n.holford
> http://www.fmhs.auckland.ac.nz/sms/pharmacology/holford
>
>
Received on Thu Nov 13 2008 - 00:26:59 EST

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