Re: [NMusers] No message

From: Julia Korell (Model Answers) <"Julia>
Date: Wed, 26 Aug 2015 11:42:42 +1000

Hi Peggy

When modelling log-transformed data, it’s useful to add a =
safeguard for IPRED to prevent taking a log of 0, e.g.:

IPRED = -5
IF (F.GT.0) IPRED = LOG(F)

Similarly, when using a proportional (CCV) error model, use the =
following to prevent division by 0:

W = IPRED
IF (W.LE.0) W = 0.0001
IRES = DV-IPRED
IWRES = IRES/W

But as Luann pointed out, for log-transformed data the additive error =
model (on log scale) is generally used (W=1), which translates to a =
proportional error on normal scale.


Best regards
Julia

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Julia Korell, PhD
Pharmacometrician
Model Answers Pty Ltd
Tel: +61 (0) 7 3221 1315
www.model-a.com.au <http://www.model-a.com.au/>
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> On 25 Aug 2015, at 1:34 pm, luann <Luann.Phillips_at_cognigencorp.com> =
wrote:
>
> Please see my comments inserted below about the values of IPRED,W, =
etc. for each type of error model
>
> I hope the modeling goes well.
>
> Luann
>
> On 8/24/2015 9:16 PM, Chiaying Lin wrote:
>> Dear NM-Users,
>> I'm a NONMEM beginner. The following are my control stream for a =
monoclonal antibody which clears via target mediated disposition. =
However, when I ran NONMEM, I didn't get minimization successful message =
(in fact, no message at all), there are also no Table output and the =
xx.g77 file contains only empty three output files. I will be =
appriciated if someone help to find mistakes. Thanks.
>>
>> Peggy
>>
>> =
--------------------------------------------------------------------------=
-------------------------------------------------------------
>> $PROBLEM **base model**
>> $DATA PKDATA.CSV IGNORE=C
>>
>> $INPUT ID TIME AMT NDV=DROP LNDV=DV EVID MDV CMT BW AGE DOSE
>>
>> $SUBROUTINE ADVAN6 TRANS1 TOL=3
>>
>> $MODEL NCOMP=2 NPAR=6
>> ;COMP=(CENTRAL DEFOBSERVATION DEFDOSE)
>> ;COMP=(PERIPH)
>>
>> $PK
>> TVVMAX=THETA(1)
>> VMAX=TVVMAX*EXP(ETA(1))
>> KM=THETA(2)
>> TVV1=THETA(3)
>> V1=TVV1*EXP(ETA(2))
>> TVV2=THETA(4)
>> V2=TVV2*EXP(ETA(3))
>> Q=THETA(5)*EXP(ETA(4))
>> S1=V1
>>
>> $DES
>> C1=A(1)/V1
>> C2=A(2)/V2
>> DADT(1)=-VMAX*C1/(KM+C1)-(Q*C1)+(Q*C2)
>> DADT(2)=(Q*C1)-(Q*C2)
>>
>> $ERROR
>> CALLFL=0
>> IPRED=LOG(F)
>> IRES=DV-IPRED
>> IWRES=IRES/IPRED
>
>
> For CCV error model
> IPRED=F
> W=IPRED
> Y=IPRED+W*ERR(1)
>
> For LOG error model
> IPRED=LOG(F)
> W=1
> Y=IPRED+W*ERR(1)
>
> For additive error model
> IPRED=F
> W=1
> Y=IPRED+W*ERR(1)
>
> For additive + CCV error model
> IPRED=F
> W=SQRT(IPRED**2*SIGMA(1,1) + SIGMA(2,2))
> Y=F + F*EPS(1)+EPS(2)
>
> The following is true for all of the above models
> IRES=DV-IPRED
> IWRES=IRES/W
>
>
>> Y=IPRED+ERR(1)
>>
>> $THETA
>> (0.1, 1.49, 5) ;VMAX (mg/hr)
>> (1, 50,300) ;KM (μg/mL)
>> (1.3, 2.72, 5) ;V1 (L)
>> (1.1, 2.43, 5) ;V2 (L)
>> (0.001, 0.095, 1) ;Q (L/hr)
>>
>> $OMEGA .025 ;VMAX
>> $OMEGA .032 ;V1
>> $OMEGA .29 ;V2
>> $OMEGA .975 ;Q
>>
>> $SIGMA
>> 0.030 ;ERR(1)
>>
>> $ESTIMATION METH=1 MAXEVAL=9999 PRINT=5 POSTHOC
>>
>> $COVARIANCE
>>
>> $TABLE ID TIME DV IPRED IWRES VMAX KM V1 V2 Q ETA1 ETA2 ETA3 ETA4 BW =
AGE NOPRINT ONEHEADER FILE=1.fit
>> $TABLE ID TIME AMT IPRED IWRES NOPRINT ONEHEADER FILE=sdtab1
>> $TABLE ID VMAX KM V1 V2 Q ETA1 ETA2 ETA3 ETA4 NOPRINT ONEHEADER =
FILE=patab1
>> $TABLE ID BW AGE NOPRINT ONEHEADER FILE=cotab1
>> =
--------------------------------------------------------------------------=
--------------------------------------------------------
>> #ID TIME AMT
>>
>>
>> NDV
>>
>>
>>
>>
>> LNDV
>>
>>
>>
>> EVID MDV CMT BW AGE DOSE
>> A-P001 0 81.3 . . 1 1 1 =
81.3 50 81.3
>> A-P001 0.25
>> 4.8 1.568616
>>
>> 1 81.3 50 81.3
>> A-P001 1
>> 18 2.890372
>>
>> 1 81.3 50
>> 81.3
>>
>> =
    LNDV=Ln-transformed con. (mcg/ml)
>
> --
> Luann Phillips | Director, Pharmacometrics
> Cognigen Corporation, a wholly owned subsidiary of Simulations Plus, =
Inc.
> 1780 Wehrle Drive, Suite 110 | Buffalo, NY 14221-7000
> Phone: 716.633.3463 x236 | Fax: 716.633.7404 | =
luann.phillips_at_cognigencorp.com <mailto:luann.phillips_at_cognigencorp.com>


Received on Tue Aug 25 2015 - 21:42:42 EDT

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