RE: WARNING 48
Mahesh,
You have what is called in other ODE solvers a "state vector",
basically a vector containing the quantities in each of the
"compartments" This state vector is advances through time from one
time point to the next. So, at if you have events at time= 1 and time
=2, at time =2, it starts with the state vector values of time = 1,
then does the integration to bring it to time = 2. But, it doesn't
know the values of the state vector until it is done. If you are
calculating something inside the $DES block, e.g.
DADT(1) = -KA*A(1)
DADT(2) = KA*A(2)-K*A(2)
CONC =A(2)/S2
You'll get this message because CONC is initially calculated, at TIME =
2, with the value of A(2) from TIME = 1, i.e. it is the wrong value for
TIME = 2. The value is still left over from the last time, it hasn't
(yet) been updated.
Further, when you change to a new subject, the value of CONC is still
left over from the last subject.
This is all OK for the minimization, you just need to be aware of it
when interpreting output, plots, tables etc. that the first value for
CONC for a subject will not be correct.
Mark
Mark Sale MD
Next Level Solutions, LLC
www.NextLevelSolns.com
Quoted reply history
> -------- Original Message --------
> Subject: [NMusers] WARNING 48
> From: "Samtani, Mahesh [PRDUS]" <[EMAIL PROTECTED]>
> Date: Mon, February 26, 2007 6:09 am
> To: [email protected]
>
> WARNING 48
>
> Dear NM group,
> I am running my own DES defined PD model and Nonmem generates the following
> warning. What does this warning mean and does it have any implications even
> if I get successful minimization.
>
> (WARNING 48) DES-DEFINED ITEMS ARE COMPUTED ONLY WHEN EVENT TIME
> INCREASES. E.G., DISPLAYED VALUES ASSOCIATED WITH THE FIRST EVENT RECORD
> OF AN INDIVIDUAL RECORD ARE COMPUTED WITH (WITH LAST ADVANCE TO) AN EVENT
> TIME OF THE PRIOR INDIVIDUAL RECORD.
>
> Kindly advice...MNS
>