Re: discussion period begins for Motion P1788.1/M002.01: Required operations
I also support the inclusion of cancelMinus and cancelPlus.
Indeed, they are not part of a closed system, but using them one can
obtain inner addition and inner subtraction operations,
which are part of a closed system. Motion 12 gives the necessary
formulae,
Svetoslav
On 14 Oct 2015 at 7:54, Ralph Baker Kearfott wrote:
Subject: Re: discussion period begins for Motion P1788.1/M002.01:
Required operations
To: Nathalie Revol <Nathalie.Revol@xxxxxxxxxxx>,
Stds-1788 <stds-1788@xxxxxxxx>
Copies to: epopova@xxxxxxxxxx, Dmitry Nadezhin
<dmitry.nadezhin@xxxxxxxxxx>
From: Ralph Baker Kearfott <rbk5287@xxxxxxxxxxxxx>
Date sent: Wed, 14 Oct 2015 07:54:18 -0500
> All,
>
> I am for including cancelMinus and cancelPlus, for practical
> reasons: (1) I have found them useful when "updating"
> sums by removing previously added terms, such as in the
> interval Gauss--Seidel method; (2) It doesn't seem to add
> complexity to the "simplified" standard.
>
> Of course, there may be counter arguments associated with them
> not being a part of a closed system, etc. I'm "all ears."
>
> Baker
>
> On 10/12/2015 09:30 AM, Nathalie Revol wrote:
> > Dear Colleagues,
> >
> > as Dmitry has moved this motion and Evgenija has seconded it,
> > (thank you to both of them), this is Motion P1788.1/M002.01:
> > the discussion period now begins and will end November 2nd.
> >
> > Best regards
> > Nathalie
> >
> >> On 12 Oct 2015, at 16:17, Evgenija Popova <epopova@xxxxxxxxxx> wrote:
> >>
> >> I second the motion "Required Operations".
> >>
> >> Evgenija Popova
> >>
> >> Institute of Mathematics and Informatics
> >> Bulgarian Academy of Sciences
> >>
> >>> P-1788:
> >>>
> >>> Does someone second this motion?
> >>>
> >>> Baker (acting as chair)
> >>>
> >>> On 10/12/2015 07:02 AM, Dmitry Nadezhin wrote:
> >>>>
> >>>> Motion "Required Operations".
> >>>>
> >>>> Operations required in all flavors of the standard IEEE 1788-2015
> >>>> are required also in the simplified standard P1788.1 .
> >>>>
> >>>> Specifically, 4 operations missed in the initial draft are required
> >> in P1788.1:
> >>>> - arithmetic operations
> >>>> roundTiesToEven(x)
> >>>> roundTiesToAway(x)
> >>>> - cancellative addition and subtraction
> >>>> cancelPlus(x,y)
> >>>> cancelMinus(x,y) .
> >>>>
> >>>> -----------------
> >>>>
> >>>> Rationale.
> >>>>
> >>>> This (together with better conformance of interval literals) permits
> >>>> more formal relation between IEEE 1788-2015 and P1788.1 .
> >>>> It makes P1788.1 become a flavor of IEEE 1788-2015
> >>>> though text of P1788.1 doesn't need to mention flavors.
> >>>> If P1788.1 satisfies requirements of IEEE 1788-2015 flavor without
> >> any exemptions
> >>>> it starts a good tradition of adding new flavors to IEEE 1788-2015.
> >>>>
> >>>> The specification of roundTiesToXXX(x) and specification
> >> cancellative operations
> >>>> doesn't add too much text to the P1788.1 .
> >>>>
> >>>> There are simple implementations of these functions.
> >>>>
> >>>> A possible implementation of roundTiesToXXX(x) operations can be
> >> found here:
> >>>>
> >> https://java.net/projects/jinterval/sources/svn/content/trunk/jinterval/p1788-launcher-java/src/main/resources/net/java/jinterval/p1788/integerFuns.c?rev=379
> >> .
> >>>> And Michel Hack wrote how to do it simpler:
> >>>> http://grouper.ieee.org/groups/1788/email/msg08423.html .
> >>>>
> >>>> There are subtleties in implementation of cancellative operations
> >>>> when the answer is nearly a one-point interval (or nearly undefined).
> >>>> See notes in subsection 12.12.5 of IEEE 1788-2015.
> >>>> Nevertheless, Marco Nehmeier suggested a solution:
> >>>> http://grouper.ieee.org/groups/1788/email/msg07858.html .
> >>>>
> >>>> --------------
> >>>>
> >>>
> >>>
> >>> --
> >>>
> >>> ---------------------------------------------------------------
> >>> 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
> >>> ---------------------------------------------------------------
> >>>
> >>>
> >
> > ------------------------------------------------------------------------------------------------------------
> >
> > Nathalie Revol INRIA Grenoble - Rhone Alpes
> > LIP - projet AriC tel: (33) 4 72 72 84 36
> > Ecole Normale Superieure de Lyon fax: (33) 4 72 72 80 80
> > 69364 Lyon Cedex 07, France Nathalie.Revol@xxxxxxxxxxx
> > http://perso.ens-lyon.fr/nathalie.revol/
> >
> > ------------------------------------------------------------------------------------------------------------
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
> --
>
> ---------------------------------------------------------------
> 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
> ---------------------------------------------------------------