The only way I know to simulate with residual variability is to use
$SIM SIMONLY
If ETAs need to be fixed, they have to be in the data file
$INPUT ,PKETA1,
CL=THETA(1)*EXP(PKETA1+0*ETA(1))
--
another option is to use mrgsolve or similar R packages (after reading
in estimated ETA values).
--
Mixed option is to simulate IPRED and then add noise in the R code after
reading IPRED.
Thank you
Leonid
On 10/8/2023 3:30 PM, Philip Harder Delff wrote:
Dear all,
I want to simulate subjects with ETAs estimated. I use the .phi file
using a $ETAS statement like:
$ETAS FILE=file.phi FORMAT=s1pE15.8 TBLN=1
As far as I understand that has to be accompanied by a $ESTIMATION step
that specifies FNLETA=2 like this:
$ESTIMATION MAXEVAL=0 NOABORT METHOD=1 INTERACTION FNLETA=2
$SIM ONLYSIM does not work with $ESTIMATION so instead I just do:
$SIMULATION (220412)
This however means that in the following from $ERROR we don't get the
ERR(1) and ERR(2) simulated and so Y=IPRED.
Y=F+F*ERR(1)+ERR(2)
I need to be able to edit the phi file to only simulate a subset of the
patients so I can't use msf based solutions. Can I somehow use $ETAS
without $ESTIMATION? Or how else can I get it to simulate the residual
variability?
Thank you,
Philip
