Minimization terminated ?

From: Navin Goyal Date: July 19, 2007 technical Source: mail-archive.com
Dear NM Users, I am using trying to model some POPPK data in NONMEM vi Sometimes I get the following message in the output file MINIMIZATION TERMINATED DUE TO ROUNDING ERRORS (ERROR=134) NO. OF FUNCTION EVALUATIONS USED: 1103 NO. OF SIG. DIGITS UNREPORTABLE But when I change the SIGDIGITS to a lower value the minimization is successful. What exactly is happening in this case ? Is there something I am missing out? what about the parameter estimates obtained in such a run ? Another question related to this is that when I bootstrap a model in wings for nonmem WFN, I get few runs with similar message where in it also says the same message as above ..MINIMIZATION TERMINATED DUE TO ROUNDING ERRORS (ERROR=134) NO. OF SIG. DIGITS UNREPORTABLE. This means that I discard these runs from the calculations ? I have attached the control stream below : $SUBROUTINE ADVAN6 TRANS1 TOL=3 $MODEL COMP=(DEPOT,DEFDOSE); COMP=(CENTRAL);PLASMA COMP=(PERIPH);PERIPHERAL $PK TVF1=THETA(1) F1=TVF1*EXP(ETA(1)) TVCL=THETA(2) CL=TVCL*EXP(ETA(2)) TVVC=THETA(3);vol of dist of drug VC=TVVC*EXP(ETA(3)) TVK20=THETA(4) K20=TVK20*EXP(ETA(4)) K12=THETA(5)*EXP(ETA(5));Abso constant K23=THETA(6)*EXP(ETA(6)) K32=THETA(7)*EXP(ETA(7)) CL=K20*VC SC=VC; OUTPUT IN ng/ml $ERROR IPRED=F IRES=DV-IPRED DEL=0 IF (IPRED.EQ.0) DEL=1 IWRE=(1-DEL)*IRES/(IPRED+DEL) Y=F+F*ERR(1);+ERR(2) $DES DADT(1)=-K12*A(1) DADT(2)=K12*A(1)-K20*A(2)-K23*A(2)+K32*A(3) DADT(3)=K23*A(2)-K32*A(3) $THETA (0.1,0.3,0.7); (75 FIXED);CL (0,550,1000);VC (0.02,0.2,2);K20 (7 FIXED);K12 (0.01 ,0.1,10);K23 (0.01,0.1,10);K32 $OMEGA (0.01);INH (0.001);CL (0.01);VC (0.01);K20 (0.01);K12 (0.01);K23 (0.01);K32 $SIGMA (0.04); $ESTIMATION METHOD=1 SIGDIGITS=2 MAXEVAL=9999 PRINT=10 POSTHOC $COV MATRIX=S $TABLE ID TIME EVID CMT IPRED IWRE IRES CL VC K20 F1 NOPRINT ONEHEADER FILE=sdtabdoc5 -- --Navin
Jul 19, 2007 Navin Goyal Minimization terminated ?
Jul 20, 2007 Nitin Mehrotra Re: Minimization terminated ?
Jul 20, 2007 Nick Holford Re: Minimization terminated ?
Jul 21, 2007 Mark Sale RE: Minimization terminated ?
Jul 21, 2007 Nick Holford Re: Minimization terminated ?
Jul 21, 2007 Mahesh Samtani RE: Minimization terminated ?
Jul 22, 2007 Jurgen Bulitta Re: Minimization terminated ?
Jul 22, 2007 Stephen Duffull RE: Minimization terminated ?