Re: Swarm Futures re-cap

[Jan Burse]

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 +

Yes troubles, in this situation often EPS comes into play,
which can easily be computed by:

  EPS=1;
  while (1+EPS!=1) {
    EPS=EPS/2;
  }

Its the greatest number X such that 1+X=1. Confusing, isn't
it! Too much wholes in the machine continuum!

So in the worst case your result is roughly 7.2*EPS, if 0.4
is represented to high and 0.6 is represented to low:

  9*0.4*(1+EPS)-6*0.6*(1-EPS)=7.2*EPS.

Best Regards
--
Jan Burse
Milchbuckstr. 1
8057 Zürich
fixnet: +41-43-268 04 03
natel: +41-76-316 46 39



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