Troubles with RNG seeds.

Question

question

Joe D asked May 12 2021 at 3:02 AM Ben Wilson commented May 19 2021 at 2:23 AM

Troubles with RNG seeds.

Hello, I have been using getstream(current) as my random seed generator but it seems to not be random as every simulation has exactly the same output. The only way I can get the outputs of my simulations to change is by changing inputs of an object (e.g. change the bottom value of my beta distribution from 2.5 to 1.5).

Am I misunderstanding getstream(current)? And is there a way for all of my simulations to be truly random and change output/random seed with every new simulation?

Thanks.

Software Version:

FlexSim 20.0.10

simulation flexsim 20.0.10 random streams

· 1

______

Cookie preferences

Your privacy is important to us and so is an optimal experience. To help us customize information and build applications, we collect data about your use of this site.

May we collect and use your data?

Learn more about the Third Party Services we use and our Privacy Statement.

Strictly necessary – required for our site to work and to provide services to you

These cookies allow us to record your preferences or login information, respond to your requests or fulfill items in your shopping cart.

YES

Improve your experience – allows us to show you what is relevant to you

These cookies enable us to provide enhanced functionality and personalization. They may be set by us or by third party providers whose services we use to deliver information and experiences tailored to you. If you do not allow these cookies, some or all of these services may not be available for you.

YES

NO

Customize your advertising – permits us to offer targeted advertising to you

These cookies collect data about you based on your activities and interests in order to show you relevant ads and to track effectiveness. By collecting this data, the ads you see will be more tailored to your interests. If you do not allow these cookies, you will experience less targeted advertising.

YES

NO

Are you sure you want a less customized experience?

We can access your data only if you select "yes" for the categories on the previous screen. This lets us tailor our marketing so that it's more relevant for you. You can change your settings at any time by visiting our privacy statement

Your experience. Your choice.

We care about your privacy. The data we collect helps us understand how you use our products, what information you might be interested in, and what we can improve to make your engagement with Autodesk more rewarding.

May we collect and use your data to tailor your experience?

Explore the benefits of a customized experience by managing your privacy settings for this site or visit our Privacy Statement to learn more about your options.

Answer 1 · 2021-05-12T03:11:22Z

James Rodgers1 answered May 12 2021 at 3:11 AM Jason Lightfoot edited May 13 2021 at 11:50 PM

Under the "Statistics" menu there is a check to "Repeat Random Number Streams". De-select this check box to have random number streams not repeat:

repeat-random-number-streams.png (14.6 KiB)

· 2

Joerg Vogel commented · May 12 2021 at 5:10 AM

And if you let run your model in an express license (demo version), it is a restricting feature and not a bug.

1 ·

Jason Lightfoot ♦♦ commented · May 13 2021 at 11:49 PM

I don't recommend doing this since if/when you encounter a problem you'll want to repeat the events.

Instead go to the experimenter and change the replication number that is seeding all the streams for the interactive run.

Then when you want to run an experiment you've already tried a couple of replications interactively.

0 ·

1620949734188.png (3.8 KiB)

1620949792701.png (3.8 KiB)

question