Re: RE: question about random seed for simulation

On 3/9/2017 6:11 PM, Faelens, Ruben (Belgium) wrote: > Hi Penny, > > Nonmem indeed calculates each subject one after the other. The random > values will therefore change. Maybe you can set the random seed every > time you simulate t=0, based on the subject ID? > > This may also depend on your data file; have you tried ordering on time > (so the first 50 rows are all t=0 for subject 1 to 50) ? > > This largely depends on the simulation software and its design: > > As an example: Simulo samples all subjects together at simulation start, > after which it runs the trial design; so the same subjects are sampled > independent of subsequent trial design. > > I do not know about other tools (TS.2, simulx, mrgsolve), maybe the > authors of these tools can specify? > > Kind regards, > > Ruben Faelens > > *From:*[email protected] > [mailto:[email protected]] *On Behalf Of *Zhu, Penny > *Sent:* donderdag 9 maart 2017 19:19 > *To:* [email protected] > *Subject:* [NMusers] question about random seed for simulation > > Dear All > > I have finished a multiple dose simulation for 600 subjects and want to > perform a single dose simulation (different sampling time) on the same > subjects (same ETA as the first simulation). I used the same seed for > the simulation step, it turned out the first subject was the same and > the rest of the subjects are not and I am not sure whether this was due > to the fact that the two simulation has different number TIME records. > If so, I wonder what is the proper way to set the simulation seed so > that the ETAs for the second simulation will be identical to the first > one. > > I know that I could output the individual parameter estimate from the > first simulation and import them into the second one. But I was > thinking if the random seed can be synchronized between the two > simulation, it could be an easier solution. > > Your help is very much appreciated! > > Thank you very much and best regards! > > * * > > *Penny (Peijuan) Zhu, Ph.D.* > > Associate Director Clinical Pharmacology > > Cell: 862-926-9079 > > PD Bio-Pharma CDMA > > Sandoz > > 1N025, 100 College Road West > > Princeton, NJ 08540 > > Information in this email and any attachments is confidential and > intended solely for the use of the individual(s) to whom it is addressed > or otherwise directed. Please note that any views or opinions presented > in this email are solely those of the author and do not necessarily > represent those of the Company. Finally, the recipient should check this > email and any attachments for the presence of viruses. The Company > accepts no liability for any damage caused by any virus transmitted by > this email. All SGS services are rendered in accordance with the > applicable SGS conditions of service available on request and accessible > at http://www.sgs.com/en/Terms-and-Conditions.aspx