Re: Simulate with ETAs from .phi and residual variability
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
Quoted reply history
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