POV-Ray : Newsgroups : povray.newusers : Will random sequence change in different environment? Server Time
28 Mar 2024 17:42:56 EDT (-0400)
  Will random sequence change in different environment? (Message 1 to 5 of 5)  
From: crowbait
Subject: Will random sequence change in different environment?
Date: 5 Jun 2016 11:10:01
Message: <web.5754407381844774bf6ff1060@news.povray.org>
Hello,

Please let me make a question about the random stream of POV-Ray.
Will it generate same sequence from same seed in other POV-Ray instance?
I would like to know if my .povs make similar images in different OS or machine
or version.
Thank you very much.


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From: Alain
Subject: Re: Will random sequence change in different environment?
Date: 5 Jun 2016 14:08:00
Message: <57546a80@news.povray.org>

> Hello,
>
> Please let me make a question about the random stream of POV-Ray.
> Will it generate same sequence from same seed in other POV-Ray instance?
> I would like to know if my .povs make similar images in different OS or machine
> or version.
> Thank you very much.
>
>

In most cases, the result will be the same.
There may be some differences if the FP processor is different due to 
possible differences in how rounding and normalisation are done.


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From: clipka
Subject: Re: Will random sequence change in different environment?
Date: 5 Jun 2016 14:35:51
Message: <57547107$1@news.povray.org>
Am 05.06.2016 um 17:08 schrieb crowbait:
> Hello,
> 
> Please let me make a question about the random stream of POV-Ray.
> Will it generate same sequence from same seed in other POV-Ray instance?
> I would like to know if my .povs make similar images in different OS or machine
> or version.
> Thank you very much.

What Alain said.
In a nutshell, the values may differ on different platforms, but only by
tiny amounts.

Of course, if you use the results to make decisions, there is a small
chance that those miniscule differences have a major effect.


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From: crowbait
Subject: Re: Will random sequence change in different environment?
Date: 5 Jun 2016 14:45:00
Message: <web.57547288b355a8a386a54a330@news.povray.org>
Alain <kua### [at] videotronca> wrote:
> In most cases, the result will be the same.
> There may be some differences if the FP processor is different due to
> possible differences in how rounding and normalisation are done.

Thank you very much. I do check for FP specs in my available PCs.
Thanks again,
crowbait


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From: crowbait
Subject: Re: Will random sequence change in different environment?
Date: 6 Jun 2016 08:35:00
Message: <web.57556dbbb355a8a3f94abd7a0@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
(snip)
> What Alain said.
> In a nutshell, the values may differ on different platforms, but only by
> tiny amounts.
>
> Of course, if you use the results to make decisions, there is a small
> chance that those miniscule differences have a major effect.

Thank you very much for more precise information.
I am glad to hear random sequences are almost same.
It is enough for my purpose.
I will take care of the corner case.

Thanks again,
crowbait


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