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: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Nick Holford > 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: [EMAIL PROTECTED] > > > > > > > > > > -- > Nick Holford, Dept Pharmacology & Clinical Pharmacology > University of Auckland, 85 Park Rd, Private Bag 92019, > Auckland, New Zealand > [EMAIL PROTECTED] tel:+64(9)923-6730 fax:+64(9)373-7090 > http://www.fmhs.auckland.ac.nz/sms/pharmacology/holford > >
