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Betr.: 20 variable limit in $INPUT

From: Ron Keizer <Ron.Keizer>
Date: Mon, 16 Mar 2009 18:23:21 +0100


Some months ago I spent a few hours investigating this same problem. Below =
are my notes. Currently I use the last approach (which is actually a =
workaround, sorry...), that will hopefully be redundant when NM7 arrives,
best regards,


approaches for using more covariates in dataset:

* using CONT method (
- Pro: easy using PsN to generate the splitted dataset
- Con: Could get it to work only in NMV, not in NMVI (reason unknown, with =
and without PsN). poorly documented in NM. Needs ID CONT DV and MDV as the =
first columns on each row.

* using Fortran script (
- Pro: in theory neat method, separate dataset for covariates.
- Con: gave problems with g77 compiler, but works with df. Needs adaptation=
 for time-changing covariates.

* row-wise incorporation in dataset using EVID=2 events.
- Pro: solves problems with above methods... Unlimited amount of covariates=
- Con: can make datasets much bigger (=slower?) when lot of covariates =
included (however, in NM6 easily switch on/off reading of covariates using =
IGNORE=...). May need extra code to avoid numerical difficulties for =
covariates that define states at t=0.

RJ Keizer, PharmD
Department of Pharmacy & Pharmacology
Slotervaart Hospital / The Netherlands Cancer Institute
Louwesweg 6, 1066 EC Amsterdam, The Netherlands
Phone: +31205124662

>>> <andreas.krause
I am looking for a solution to get around the limit of 20 input =
in nonmem.
The message you get with more than 20 variables in $INPUT is this:

STOP 4 statement executed

I did not find anything in the archives or on the Web. I recall having
successfully done that in nonmem V, and I think it was about changing =
value of 20 to another value in a few files.
My original naive idea was that this was just a single change to the =
file in nm VI but that seems to not be the case.

To keep the discussion focused, I am not looking for workarounds like
solutions with concatenated values and an indicator variable.
For a change I am trying to get the software to adapt to the user's =
instead of the usual opposite situation.

Thanks for any pointers.



Andreas Krause, PhD
Lead Scientist Modeling and Simulation

Actelion Pharmaceuticals Ltd
Gewerbestrasse 16
CH-4123 Allschwil

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Received on Mon Mar 16 2009 - 13:23:21 EDT

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