Re: midpoint
On 2012-03-07 08:27:34 -0800, Dan Zuras Intervals wrote:
> Thus, although things like midpoint may be easily
> well defined among the Reals, we have to ask
Among the reals, the midpoint of an unbounded interval or Empty
is not well defined.
> ourselves: What is the best representation of
> these results within our finite floating-point
> systems & the intervals we construct out of them?
>
> And, in this context, the word "best" should not
> be interpreted as "closest" but as "most useful".
> So: What is the most useful answer?
>
> In general, this will be a matter of some opinion
> & debate (obvious from the length of this discussion
> already). But I think your principle of avoiding
> NaNs & infinities in so far as is possible is a good
> place to start.
>
> I believe that infinities can largely be avoided &
> that NaNs can be avoided altogether. But I must
> admit I am not quite sure about the NaNs.
But what if the most useful answer is to warn the user that he did
something wrong? And what is the most useful way to do that?
--
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)