RE: M3 method with log transformed data
Dear Ayappa,
This looks fine. However, with NONMEM 7.2 you can also write it as below.
Estimating SIGMA rather than fixing it and estimate a multiplicative THETA
may have speed advantages (and simpler coding for the new methods).
$ERROR
CALLFL=0
IPRED=-3
IPRED=LOG(F)
W=SIGMA(1,1) ;LOG ADDITIVE ERROR
LOQ=LOG(0.03);loq is 0.3
DUM=(LOQ-IPRED)/W
CUMD=PHI(DUM)
IF (BQL.EQ.0) THEN
IWRES = (DV-IPRED)/W
F_FLAG=0
SIMDV = LOG(F)+ERR(1)
Y=F+W*ERR(1)
ENDIF
IF (BQL.EQ.1) THEN
IWRES = 0
F_FLAG=1
Y=CUMD
ENDIF
$EST METHOD=COND INTER LAPLACIAN
$SIGMA 1
Best regards,
Mats
Mats Karlsson, PhD
Professor of Pharmacometrics
Dept of Pharmaceutical Biosciences
Faculty of Pharmacy
Uppsala University
Box 591
75124 Uppsala
Phone: +46 18 4714105
Fax + 46 18 4714003
Quoted reply history
From: [email protected] [mailto:[email protected]] On
Behalf Of Ayyappa Chaturvedula
Sent: 22 November 2012 00:07
To: [email protected]
Subject: [NMusers] M3 method with log transformed data
Dear Group,
I want to implement M3 method with log transformed data. I want to use the
additive error model in log domain and wrote the following code and the runs
are fine. I want to make sure that I am doing this right.
$ERROR
CALLFL=0
IPRED=-3
IPRED=LOG(F)
W=THETA(4) ;LOG ADDITIVE ERROR
LOQ=LOG(0.03);loq is 0.3
DUM=(LOQ-IPRED)/W
CUMD=PHI(DUM)
IF (BQL.EQ.0) THEN
IWRES = (DV-IPRED)/W
F_FLAG=0
SIMDV = LOG(F)+W*ERR(1)
Y=F+W*ERR(1)
ENDIF
IF (BQL.EQ.1) THEN
IWRES = 0
F_FLAG=1
Y=CUMD
ENDIF
$EST METHOD=COND INTER LAPLACIAN
$SIGMA 1 FIX
Thank you for your help.
Regards,
Ayyappa