[R] Getting different results with set.seed()

[Shah Alam]

Dear All,

Thanks a lot for your valuable suggestions. I am going to implement one by
one.

Jan:

Yes, I am using the "doParallel" package for parallelization. I will let
you know the results after implementing all the given suggestions.

Best regards,
Shah



On Thu, 19 Aug 2021 at 11:57, Jan van der Laan <rhelp using eoos.dds.nl> wrote:

>
>
> What you could also try is check if the self coded functions use the
> random generator when defining them:
>
> starting_seed <- .Random.seed
>
> Step 1. Self-coded functions (these functions generate random numbers as
> well)
>
> # check if functions have modified the seed:
> all.equal(starting_seed, .Random.seed)
>
> Step 2: set.seed (123)
>
>
>
> What has also happened to me is that some of the functions I called had
> their own random number generator independent of that of R. For example
> using one in C/C++.
>
> Do your functions do stuff in parallel? For example using the parallel
> or snow package? In that case you also have to set the seed in the
> parallel workers.
>
> Best,
> Jan
>
>
>
>
>
>
>
>
>
> On 19-08-2021 11:25, PIKAL Petr wrote:
> > Hi
> >
> > Did you try different order?
> >
> > Step 2: set.seed (123)
> >
> > Step 1. Self-coded functions (these functions generate random numbers as
> well)
> >
> > Step 3: Call those functions.
> >
> > Step 4: model results.
> >
> > Cheers
> > Petr.
> >
> > And BTW, do not use HTML formating, it could cause problems in text only
> list.
> >
> >
> > From: Shah Alam <dr.alamsolangi using gmail.com>
> > Sent: Thursday, August 19, 2021 10:10 AM
> > To: PIKAL Petr <petr.pikal using precheza.cz>
> > Cc: r-help mailing list <r-help using r-project.org>
> > Subject: Re: [R] Getting different results with set.seed()
> >
> > Dear Petr,
> >
> > It is more than 2000 lines of code with a lot of functions and data
> inputs. I
> > am not sure whether it would be useful to upload it. However, you are
> > absolutely right. I used
> >
> > Step 1. Self-coded functions (these functions generate random numbers as
> well)
> >
> > Step 2: set.seed (123)
> >
> > Step 3: Call those functions.
> >
> > Step 4: model results.
> >
> > I close the R session and run the code from step 1. I get different
> results
> > for the same set of values for parameters.
> >
> > Best regards,
> > Shah
> >
> >
> >
> >
> > On Thu, 19 Aug 2021 at 09:56, PIKAL Petr <mailto:petr.pikal using precheza.cz>
> > wrote:
> > Hi
> >
> > Please provide at least your code preferably with some data to reproduce
> > this behaviour. I wonder if anybody could help you without such
> information.
> >
> > My wild guess is that you used
> >
> > set.seed(1234)
> >
> > some code
> >
> > the code used again
> >
> > in which case you have to expect different results.
> >
> > Cheers
> > Petr
> >
> >> -----Original Message-----
> >> From: R-help <mailto:r-help-bounces using r-project.org> On Behalf Of Shah
> Alam
> >> Sent: Thursday, August 19, 2021 9:46 AM
> >> To: r-help mailing list <mailto:r-help using r-project.org>
> >> Subject: [R] Getting different results with set.seed()
> >>
> >> Dear All,
> >>
> >> I was using set.seed to reproduce the same results for the discrete
> event
> >> simulation model. I have 12 unknown parameters for optimization (just a
> >> little background). I got a good fit of parameter combinations. However,
> >> when I use those parameters combinations again in the model. I am
> getting
> >> different results.
> >>
> >> Is there any problem with the set.seed. I assume the set.seed should
> >> produce the same results.
> >>
> >> I used set.seed(1234).
> >>
> >> Best regards,
> >> Shah
> >>
> >>        [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
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> >> PLEASE do read the posting guide http://www.R-project.org/posting-
> >> guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> >>
> >> ______________________________________________
> >> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

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