NONMEM Users Network Archive

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[NMusers] Re: Random number generation

From: Tingjie Guo <iam_at_tingjieguo.com>
Date: Wed, 5 Jun 2019 10:08:44 +0000

Hi Sebastien,

It worked perfectly for me in $ERROR, but I tested it on NONMEM 7.4.3. Maybe nm version matters.

Warm regards,
Tingjie

From: Sebastien Bihorel <sebastien.bihorel_at_cognigencorp.com>
Date: Monday, 3 June 2017 at 22:54
To: Tingjie Guo <iam_at_tingjieguo.com>
Cc: "nmusers_at_globomaxnm.com" <nmusers_at_globomaxnm.com>
Subject: Re: Random number generation


Thanks Tingjie for your suggestion

Unfortunately, as is, the suggested code is rejected by NONMEM 7.3 if used in $ERROR. Some additional setup calls might be required.

An (admittedly heavy-handed) alternative that actually works is to create and import a fortran routine (see NONMEM help topic about FUNCA, or VECTRA).

runif.f90:
      FUNCTION FUNCA(X,X1,X2)
      USE SIZES, ONLY: DPSIZE
      REAL(KIND=DPSIZE) :: X,X1,X2,FUNCA
      FUNCB = RAND()
      RETURN
      END

Control stream:
...
$SUBROUTINES ADVAN_ TRANS_ OTHER=runif.f90
...
$ERROR
  VECTRA(1) = 0
  VECTRA(2) = 0
  VECTRA(3) = 0

  RND = FUNCA(VECTRA)
...

________________________________
From: "Tingjie Guo" <iam_at_tingjieguo.com>
To: "Sebastien Bihorel" <sebastien.bihorel_at_cognigencorp.com>, nmusers_at_globomaxnm.com
Sent: Monday, June 3, 2019 12:58:56 PM
Subject: Re: Random number generation

Hi Sebastien,

As far as I know, you could write verbatim code to generate random numbers during estimation. E.g:

$PK|$DES|$ERROR
RAN = any value ; initialization
"RAN = RAND(0) ; start verbatim code

A random number between 0 and 1 from uniform distribution will be assigned to RAN. This function is called for each record of your input data. I believe it's also possible to call it more/fewer times through checking ICALL.

Warm regards,
Tingjie




________________________________
From: owner-nmusers_at_globomaxnm.com <owner-nmusers_at_globomaxnm.com> on behalf of Sebastien Bihorel <sebastien.bihorel_at_cognigencorp.com>
Sent: Thursday, May 30, 2019 12:34
To: nmusers_at_globomaxnm.com
Subject: [NMusers] Random number generation


Hi,

Is it possible for NONMEM to generate a random number during an estimation run?

Thank you

Sebastien Bihorel


Received on Wed Jun 05 2019 - 06:08:44 EDT

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