Re: Do I have a second? Re: Position: That the Standard for Computing with Intervals Have Only One Level 1 Requirement: Containment
Nick, Dan,
On 8/3/2011 4:13 PM, N.M. Maclaren wrote:
> On Aug 3 2011, Dan Zuras Intervals wrote:
>>
.
.
.
>>
>> The one and only level 1 implementation requirement
>> must be to enclose the smallest set of values (the
>> containment set) that must be contained in the
>> interval result of any evaluated arithmetic
>> expression or function defined therefrom.
>>
>> While I might use less tortured prose, it sound to me like
>> the specification he desires is to return the tightest
>> interval that the working precision permits.
>
> In which case I misunderstood its intent! I understood it to mean
> that only containment is required, and the actual size of the interval
> is not a requirement (merely a quality of implementation issue). I
> agree that the text is confusing.
>
My understanding from corresponding with Bill is that
he actually meant that the size of the interval
is just a quality of implementation issue. Another aspect
of what he was advocating to me was that it is of primary
importance to know (or define) precisely what is being
contained, for each operation or function. Thus, my understanding
is there are two aspects: we may agree or disagree with
one or the other separately.
(Bill has told me he may not be able to respond to the list
for a while.)
Best regards,
Baker
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Ralph Baker Kearfott, rbk@xxxxxxxxxxxxx (337) 482-5346 (fax)
(337) 482-5270 (work) (337) 993-1827 (home)
URL: http://interval.louisiana.edu/kearfott.html
Department of Mathematics, University of Louisiana at Lafayette
(Room 217 Maxim D. Doucet Hall, 1403 Johnston Street)
Box 4-1010, Lafayette, LA 70504-1010, USA
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