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Vensim 8 without single precision?

Posted: Wed Nov 06, 2019 12:05 pm
by pav80
Greetings,

On this site https://vensim.com/september-newsletter ... -releases/ it mentions
"All configurations of Vensim now use double floating point precision for both calculations and results storage"

So does that mean as of Vensim 8, single precision is no longer available or it is possible to select it as an option?

Asking because this link https://www.vensim.com/documentation/24350.htm mentions
"For large models the double precision version of Vensim essentially takes twice the memory, so it should be used with discretion. For most business models there seems little to be gained from the added precision."

Thank you.

Re: Vensim 8 without single precision?

Posted: Wed Nov 06, 2019 12:45 pm
by Administrator
Correct, single precision is no longer an option. Due to some of the code in Vensim, the 64 bit version of Vensim has to be double precision.

Re: Vensim 8 without single precision?

Posted: Wed Nov 06, 2019 2:34 pm
by pav80
Thank you for the confirmation.

Do you also confirm that "For large models the double precision version of Vensim essentially takes twice the memory, so it should be used with discretion. For most business models there seems little to be gained from the added precision." ? Taken from https://www.vensim.com/documentation/24350.htm

Perhaps this link needs to be updated since single precision is no longer available.

Re: Vensim 8 without single precision?

Posted: Wed Nov 06, 2019 2:38 pm
by Administrator
It's not quite double the memory. It depends on the model and how many variables are being stored, plus how often the values change.

Re: Vensim 8 without single precision?

Posted: Wed Nov 06, 2019 2:55 pm
by pav80
Thanks Aministrator

Re: Vensim 8 without single precision?

Posted: Wed Nov 06, 2019 4:10 pm
by tomfid
Also, the memory limit is only significant for very large models, and that's now relieved by the availability of 64-bit Vensim, which can access memory far exceeding what's practical to run.

Re: Vensim 8 without single precision?

Posted: Wed Nov 06, 2019 4:12 pm
by pav80
Thanks Administrator