Re: Replacement of values during simulation
Elba,
It's hard to understand what you are doing because you do not give all the details e.g. how is IPRED computed? I am guessing it might be LOG(F)?
In the ICALL.EQ.4 block it would be clearer (to me) if you wrote the following:
IF (IPRED.LT.LLOQ) THEN
Y=LLOQ
ENDIF
What do you mean by "I also try to use the code that Nick send me but it did not work"? What exactly happens? Why do you think it does not work?
Nick
Quoted reply history
On 25/04/2011 8:08 p.m., elba romero wrote:
> Dear Nathan and Nick:
>
> Thank you very much for your help. Finally I'm exploring the model under this conditions, and as Nathan explained before, I simulate the effect of an LOQ in my resulting dataset. The final code is this:
>
> LLOQ = LOG(0.020) ;LOW LIMIT OF QUANTIFICATION
>
> Y=IPRED+W*EPS(1)
>
> IF (ICALL.EQ.4)THEN ;Required to simulate
> IF (F.NE.0) Y=LOG(F)
> IF(Y.LE.LLOQ) THEN;Required to replace values lower or equal than LOQ
> Y = LLOQ
> ENDIF
> ENDIF
>
> This instruction allow me to work with PsN and "play around" to know my model. I also try to use the code that Nick send me but it did not work. I wonder where is the problem, just to close the circle...
>
> Elba.
>
> ------------------------------------------------------------------------
> Date: Sun, 24 Apr 2011 21:48:30 -0500
> Subject: Re: [NMusers] Replacement of values during simulation
> From: [email protected]
> To: [email protected]
> CC: [email protected]
>
> Elba,
>
> In the $ERROR block you can add code such as the following:
>
> Y=F + F*ERR(1) + ERR(2)
> ; Replace values below -3.9 with -3.0
> IF(Y.LE.-3.9) THEN
> Y=-3.0
> ENDIF
>
> This can often be used to simulate the effect of an LOQ on the resulting dataset.
>
> Good luck!
> Nathan
>
> --
> Nathan S. Teuscher, PhD
> Founder, PK/PD Associates
> www.learnpkpd.com http://www.learnpkpd.com/
> blog.learnpkpd.com http://blog.learnpkpd.com/
> [email protected] <mailto:[email protected]>
> Twitter: www.twitter.com/learnpkpd http://www.twitter.com/learnpkpd
>
> Facebook: www.facebook.com/pages/Learn-PKPD < http://www.facebook.com/pages/Learn-PKPD/184975014854559?v=wall > YouTube Channel: www.youtube.com/learnpkpd < http://www.youtube.com/learnpkpd > On Sat, Apr 23, 2011 at 11:53 AM, elba romero < [email protected] < mailto: [email protected] >> wrote:
>
> Dear nonmemusers:
>
> I’m performing some simulations in order to verify the behaviour
> of my model. My iDV and DV are time an concentration respectively.
>
> In my case it would be useful to replace all simulated data (DV)
> that have values less or equal than -3.9 by this value: -3.0.
>
> Does anybody could help me how to give this instruction to NONMEM7
> in order to replace all this values during simulation?
>
> Thank you in advance!
>
> Elba
>
> PhD student
>
> UNAV
--
Nick Holford, Professor Clinical Pharmacology
Dept Pharmacology& Clinical Pharmacology
University of Auckland,85 Park Rd,Private Bag 92019,Auckland,New Zealand
tel:+64(9)923-6730 fax:+64(9)373-7090 mobile:+64(21)46 23 53
email: [email protected]
http://www.fmhs.auckland.ac.nz/sms/pharmacology/holford