Re: Motion 52: final "Expressions" text for vote
Yes.
For a system of real, not extended real intervals, the domain of
div(x,y) and recip(x) can be R^2 and R, respectively. See Table 9.1 on
page 21.
The ranges of asin, acos, atan, and atan2 functions are unnecessarily
narrow.
These are just two examples.
There are many more, including the ability to replace code for a given
expression or set of expressions with different code as long as the new
code always returns an enclosure of the containment set defined by the
original code. Of course, this requires the containment set of any
existing code to be defined, which has yet to be done; where the
containment set is just the smallest set of values that must be included
in the result of any interval computation.
Therefore Section 9 makes it impossible for alternative interval systems
to be standard conforming flavors.
My fundamental problem with the draft standard is that I believe it will
accomplish the opposite of what the authors intended it to accomplish.
That is, rather than increasing acceptance of computing with intervals,
I believe in anything like its present form, the draft standard will
decrease the acceptance of computing with intervals. Its complexity
exposes the fact that the mathematical foundation remains incomplete.
Cheers,
Bill
On 11/23/13 8:28 PM, Dmitry Nadezhin wrote:
Are there some more issues there that may prevent developing
containment-set flavour or other flavour you are developing in future ?