To Ruben's question: mrgsolve simulates the subjects up front as well. The subjects are identical across runs if the seed and number of subjects does not change.
An illustration: http://mrgsolve.github.io/2017/03/09/reproducible-results-with-set.seed/ Best regards, Kyle On Thu, Mar 9, 2017 at 5:11 PM, Faelens, Ruben (Belgium) < ruben.fael...@sgs.com> 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:* owner-nmus...@globomaxnm.com [mailto:owner-nmus...@globomaxnm.com] > *On Behalf Of *Zhu, Penny > *Sent:* donderdag 9 maart 2017 19:19 > *To:* nmusers@globomaxnm.com > *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 <(862)%20926-9079> > > > > 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 > -- Kyle Baron, PharmD, PhD Senior Scientist Metrum Research Group
