Re: Swarm Futures re-cap

[M Lang / S Railsback]

Gary Polhill wrote:
> 
> Now that I've just found a bug in our model that I've traced back to floating 
> point arithmetic [e.g. (9 * 0.4) - (6 * 0.6) = 4.44089E-16, whilst 0.4 + 0.4 
> + 0.4 + 0.4 + 0.4 + 0.4 + 0.4 + 0.4 + 0.4 - 0.6 - 0.6 - 0.6 - 0.6 - 0.6 - 0.6 
> = -6.66134E-16 -- not even consistent in which side of 0 it is... plus, 0.4 + 
> 0.4 + 0.4 - 0.6 + 0.4 - 0.6 + 0.4 + 0.4 + 0.4 + 0.4 + 0.4 - 0.6 - 0.6 - 0.6 - 
> 0.6 = -2.22045E-16, so even the order matters!], I wonder if one of the 
> standard libraries Swarm should provide is some kind of proper treatment of 
> floating point arithmetic, or perhaps even representing numbers as Integer, 
> Rational, Surd and Real classes somehow. All I know is I'm never trusting 


A learning opportunity for me: What is a Surd number?

Steve

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