Re: Markov model dataset
Here iis an explanation of why the error messages were being produced
by PREDPP.
At my request, Achim send me the $MODEL statement from the control
stream. $MODEL NCOMP = 4 COMP=(G0) COMP=(G1) COMP=(G2) COMP=(G3)
Compartment 1 is the default compartment for doses and observations,
because no compartment has the name CENTRAL or the attribute DEFOBS.
PREDPP always needs to compute a scaled compartment amount as the
argument F for the ERROR routine. When compartment 1 is off and PREDPP
needs to get the prediction from compartment 1 , the error messages
are produced.
0DATA REC 4: COMPARTMENT ASSOCIATED WITH THE PREDICTION IS OFF 0DATA
REC 5: COMPARTMENT ASSOCIATED WITH THE PREDICTION IS OFF 0DATA REC
6: COMPARTMENT ASSOCIATED WITH THE PREDICTION IS OFF
Here's a work around, as Ahmed Suleiman suggested:
$MODEL NCOMP = 5 COMP=(G0) COMP=(G1) COMP=(G2) COMP=(G3)
COMP=(DUMMY,DEFOBS)
Also add to the end of the $DES block: DADT(5)=0
Now compartment 5 is default for observations and there are no
error messages.
Martin Bergstrand made a number of suggestions. The one that is directly
related to these error messages is to use "a EVID = 4 dose to reset all
compartments rather than resetting them 1 by 1."
EVID=4 is "reset and dose". All compartments are set to 0, and then the
dose is applied to compartment 1.
The data would look like this. No changes to $MODEL or $DES are needed,
because compartment 1 is never turned off.
C ID TIME DOSE DV EVID CMT AMT MDV 1 0 0
0 1 1 1 1 1 1 50 1 0 1 0
0 1 1 50 0 4 1 1 1 1 1 50
0 2 2 0 1 1 1 50 0 2 3 0
1 1 1 50 0 2 4 0 1
Martin made other valuable suggestions but I am just trying to explain
the error messages.