Milan Klöwer

Who wins if Bart Simpson, Son Goku and Johnny Bravo fight about decimal precision? And why on Earth is that related to their haircuts??

Posits are a recently proposed alternative to the widely used floating-point numbers. The approach: a mathematically clearer design of computer-representable numbers. The aim: More precision with fewer bits. If we hap a CPU based on posits would there be any benefit for the weather and climate forecasting community?

Yes, and the reason is quite simple: Posits have a higher decimal precision (i.e. the decimal places that you have at least correct after unavoidable rounding errors) around 1 and yet a wide range of representable numbers. Basically, this means you get always precise answer if you don't pay attention where (on the real axis) you perform calculations. However, if you make sure that you scale your calculation to performed around 1 you win several decimals places of accuracy!

Guess now, what happens in many fluid simulations? ;)

(copyright for the cartoon pictures by somebody else...)

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