Discussion on numerical accuracy

[ocramz]

"How to produce numerically stable/reliable Haskell programs? "

• Numerically stable summation : Numeric.Sum in https://hackage.haskell.org/package/math-functions
  • case in point:

> foldr (+) 0 [1.0, 10.0e100, 1.0, (-10.0e100)]
1.0

> foldl (+) 0 [1.0, 10.0e100, 1.0, (-10.0e100)]
0.0

import Numeric.Sum -- math-functions 
> Numeric.Sum.sum kbn [1.0, 10.0e100, 1.0, (-10.0e100)] 2.0