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Re: A late question Re: P1788.1/M001.01: voting period begins

All,

I know there is a process for submitting errata to standards.  This
may be easy, since we would only be changing terminology, not normative
substance.  I'll investigate this with regard to 1788.

Regarding 1788.1, I like Vladik's suggestion to simply use "range" for
this concept.

Best regards,

Baker

On 12/01/2015 09:46 PM, Kreinovich, Vladik wrote:

I googled for "natural interval extension", the first link is to Wikipedia page on interval computation, which gives exactly the same definition as Baker mentioned -- the result of applying naïve interval arithmetic to the original expression

If I understand Ned correctly, while this problem surfaced only now, the same somewhat confusing terminology is used in the already approved 1988 standard, so if we change the definition of natural extension in the new simplified standard, we will get a contradiction with the original 1788 text.

So why don't we just call it the range, and avoid using the potentially confusing term "natural interval extension"?

P.S. Now I understand why one of the students in my recent graduate interval computations class, in one of his assignments, used the term "natural interval extension" not in the sense that I taught (via straightforward application of interval arithmetic), but as a synonym for range. I was not happy with this, and got confused, but looks like he was more attentive than I was in reading some of my handouts :-(

-----Original Message-----
From: stds-1788@xxxxxxxx [mailto:stds-1788@xxxxxxxx] On Behalf Of Nedialkov, Ned
Sent: Tuesday, December 01, 2015 11:30 AM
To: Ralph Baker Kearfott <rbk5287@xxxxxxxxxxxxx>
Cc: Stds-1788 <stds-1788@xxxxxxxx>
Subject: Re: A late question Re: P1788.1/M001.01: voting period begins

Baker et al,


On Dec 1, 2015, at 7:38 AM, Ralph Baker Kearfott <rbk5287@xxxxxxxxxxxxx> wrote:

Ned et al,

Ouch! I fear I have been truant in reading this.
At the beginning of 4.4.4, Rge(f | \x) is used in defining the natural
interval extension.  Is this notation defined elsewhere in the
document,



on the previous page


and does this mean the range of f
over \x?


Yes.


  If so, the term natural interval extension is used differently from
the way I have seen it used most often.
(My idea of "natural interval extension" is to simply plug in the
interval and do the interval arithmetic, thus resulting in an
overestimation, due to interval dependency, of the range.
The term I have seen used most often for the range of f is the "united
extension," as in e.g. Ratschek and Rokne's book.



I am afraid you are right. I tried to be consistent with the full standard, but I also had the same question.  Any thoughts by others?

Regards,
Ned




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Ralph Baker Kearfott,   rbk@xxxxxxxxxxxxx   (337) 482-5346 (fax)
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