RE: [NMusers] $Error log transformed

From: Andrzej Bienczak <andrzej.bienczak_at_googlemail.com>
Date: Fri, 16 Dec 2016 13:21:27 +0200

Hi,

 

This problem was discussed before on NMUSERS, here's a link with code
suggested by Leonid Gibiansky and Mats Karlsson (code allowing for a
combined - additive and proportional error in log space):

 

http://www.cognigencorp.com/nonmem/nm/98may202004.html

 

You model the log transformed data - so the DV is actually log
concentration. You estimate in linear space and log transform the estimated
concentrations when you define the Y as in the code in the link above.

 

Regards,

Andrzej

 

Andrzej Bienczak

MSc, MPharm, DiplPharm

Pharmacometrics Group

Division of Clinical Pharmacology

Department of Medicine

University of Cape Town

 

K45 Old Main Building

Groote Schuur Hospital

Observatory, Cape Town

7925 South Africa

phone: +27 21 650 4861

mobile: +27 839 842 675

email: andrzej.bienczak_at_gmail.com <mailto:andrzej.bienczak_at_gmail.com>

 

 

From: owner-nmusers_at_globomaxnm.com [mailto:owner-nmusers_at_globomaxnm.com] On
Behalf Of Katrin Volz
Sent: 16 December 2016 11:35 AM
To: nmusers_at_globomaxnm.com
Subject: [NMusers] $Error log transformed

 

Dear All,

 

I would like to model my data log transformed.

So far, I already found some suggestions for this problem here but none of
them worked in my case - probably I did sth. wrong.

 

I would be very happy if someone could help me with changing my error model,
which I assume has to be changed.

(I also assume that the dataset has to be changed from DV to LOG(DV)?)

 

So, here is the code I used so far (not log transformed):

 

$ERROR

IPRED = F ;IPRED drug in
the central compartment

IF (CMT.EQ.5) IPRED = A(5) ;IPRED second drug in 5th
compartment

 

DEL=0

IF (IPRED.EQ.0) DEL=0.0001

W = F

IRES = DV - IPRED

IWRES = IRES /(W + DEL)

 

Y = IPRED + IPRED * EPS(1) ; error drug in
the central compartment

IF (CMT.EQ.5) Y = IPRED + IPRED * EPS(2) ; error second drug in 5th
compartment

 

It would be great to get some help.

Thanks!

Katrin

 

 

 

 



Received on Fri Dec 16 2016 - 06:21:27 EST

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