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.alamsola...@gmail.com>
Sent: Thursday, August 19, 2021 10:10 AM
To: PIKAL Petr <petr.pi...@precheza.cz>
Cc: r-help mailing list <r-help@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.pi...@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-boun...@r-project.org> On Behalf Of Shah Alam
Sent: Thursday, August 19, 2021 9:46 AM
To: r-help mailing list <mailto:r-help@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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