HP calcs are really not that accurate..

[AlexFekken]

(12-03-2017 11:39 PM)ttw Wrote:  there are two common operations that shrink intervals

And any function with the absolute value of the derivative (uniformly) less than 1 should do that too.

Chosing the right algorithms (e.g. forward vs backward iterations) will be important to keep the interval sizes under control. Of course this has always been the case but interval arithmetic would show the impact more clearly, i.e. it would help making the right choices and justifying them...