From: "Banken, Ludger {PDBS~Basel}" <LUDGER.BANKEN@Roche.COM>

Subject: ADVAN9: error in LSODI1: CODE 205

Date: Mon, 12 Oct 1998 16:58:29 +0200

Dear NONMEM users,

using ADVAN9, in one problem NONMEM V stops after a few iterations with the following error message:

PRED EXIT CODE = 1

INDIVIDUAL NO. 37 ID=0.20101000E+05 (WITHIN-INDIVIDUAL) DATA REC

NO. 24

THETA=

1.94E-02 8.66E-02 1.70E+01 2.44E+01 1.94E+00 1.90E-01

9.72E+01 7.58E-02 2.43E-01 9.14E-02 4.97E-02

ERROR IN LSODI1: CODE 205

PROGRAM TERMINATED BY OBJ

MESSAGE ISSUED FROM ESTIMATION STEP

Does anybody know the meaning of this error message and how to circumvent it?

Best regards,

Ludger

Biometrics (PDBS, 74/4.OG W)

Pharma Development

F. Hoffmann La Roche Ltd

Grenzacherstrasse 124

CH-4070 Basel, Switzerland

Phone: ++41 61 68 87363; Fax: ++41 61 68 85335; E-mail:

Ludger.Banken@roche.com

****

From: alison@c255.ucsf.EDU (ABoeckmann)

Subject: Re: ADVAN9: error in LSODI1: CODE 205

Date: Mon, 12 Oct 1998 15:01:52 -0700 (PDT)

This message indicates some sort of numerical difficulty obtaining the solution to the system of differential/algebraic equations.

Since it happens after a few iterations, it is likely that NONMEM has tried some values of theta that are difficult for PREDPP to compute with. Perhaps they are too far from the initial estimates.

On the $ESTIM record, try the option NOABORT. This will instruct NONMEM to try different thetas ("theta recovery").

If you are already using NOABORT, then one would have to look more closely at the problem. It might be possible to bound the thetas or (better) improve the model.

Even if theta recovery works and NONMEM is able to reach a minimum, a large number of error messages in the PRDERR file may indicate that there was trouble reaching the minimum and the model needs to be improved.