From: "=?big5?B?YmVhdXR5ZW15?=" <beautyemy@sinamail.com>
Subject: LOG...
Date: Wed, 19 Sep 2001 20:23:55 +0800

Dear NONMEM users:
As a beginer of NONMEM, I have a problem of using LOG(natral log). It seems that NONMEM can't regnize LOG......

What should I do??
Thanks for any suggestion.....
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From: Luann Phillips <luann.phillips@cognigencorp.com>
Subject: Re: LOG..
Date: Wed, 19 Sep 2001 11:35:27 -0400

I have used LOG in NONMEM frequently so I'm curious about how you're
using it and what error messages you are receiving. I know that NONMEM
will accept Y=LOG(F). However, some platforms (depending on the FORTRAN
compiler and its options) will terminate the run when F=0 (which
frequently happens on the first dose record) because LOG(0) = negative
infinity. To prevent termination of a run because F=0 for dose records,
you can try the following:

IF(AMT.NE.0) TPRED=F+1 ;dose record
IF(AMT.EQ.0) TPRED=F ;event record

Y = TPRED + ESP(1)

Luann Phillips
Cognigen Corporation
Manager of Pharmacometrics R&D
395 Youngs Rd.
Williamsville, NY 14221
email: Luann.Phillips@cognigencorp.com
Voice: (716) 633-3463 ext. 236
Fax: (716) 633-7404

 

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From: Yuying Gao <ygao@pharsight.com>
Subject: RE: LOG..
Date: Wed, 19 Sep 2001 09:18:55 -0700

You can try the following:

$ERROR
TY=3DF
IF(F.GT.0) THEN
TY=3DLOG(F)
ELSE
TY=3D0
ENDIF
Y=3DTY+EPS(1)

--------------------------------
Christine Y. Gao, M.D., Ph.D.
Consulting Group
Pharsight Corporation
800 El.Camino Real, Suite 200
Mountain View, CA 94040
Phone: (650)314-3848
Fax: (650)314-3810
E-mail: ygao@pharsight.com
http://www.pharsight.com

 

 

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From: Luann Phillips <luann.phillips@cognigencorp.com>
Subject: Re: LOG..
Date: Wed, 19 Sep 2001 13:09:23 -0400

The code below can alter the objective function value because it could
change the predicted value for an event record.

Luann Phillips

> Yuying Gao wrote:
>
> You can try the following:
>
> $ERROR
> TY=F
> IF(F.GT.0) THEN
> TY=LOG(F)
> ELSE
> TY=0
> ENDIF
> Y=TY+EPS(1)

 

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From: Alan Xiao <Alan.Xiao@cognigencorp.com>
Subject: Re: LOG..
Date: Wed, 19 Sep 2001 17:09:36 -0400

Be careful to use ".EQ." function in Fortran. You might want to use (ABS(AMT - ????) .LT. ??? ) instead of
(AMT.EQ.0).

Alan.
--
***** Alan Xiao, Ph.D ***************
***** PK/PD Scientist ***************
***** Cognigen Corporation **********
***** Tel: 716-633-3463 ext 265 ******

 

*****

 

 

From: "Piotrovskij, Vladimir [JanBe]" <VPIOTROV@janbe.jnj.com>
Subject: RE: LOG..
Date: Thu, 20 Sep 2001 08:22:32 +0200

$ERROR CALLFL =3D 0
requests $ERROR to be called with observation records only (AMT=3D0)

Best regards,
Vladimir