Re: mid-rad, inf-sup, a caution...

[Ralph Baker Kearfott <rbk@xxxxxxxxxxxx>]

Nate et al,

Please see my inserted comments.

Baker

On 5/11/2010 09:27, Nate Hayes wrote:
> John Pryce wrote:
> > A.
.
.
.
> > systems, based on mid-rad formats?
>
> Has anyone in this forum ever worked with a mechanical engineer or
> architect, or seen the computer software tools they use? In those
> applications and domains, tolerancing of parts is almost always done in
> mid-rad, e.g.,
> http://www.youtube.com/watch?v=H7f5cjspuAs&feature=related
> we should be so lucky that some of the largest and most successful software
> companies in the world, such as Autodesk, Dassault Systems, Parametric
> Technology, etc. would some day use our P1788 standard. Having at least an
> interchange format for mid-rad with standardized conversion rules I suspect
> would be a minimal requirement.
>
> I would also point out that at least in this sense, mid-rad as an
> "interchange format" is already a global, multi-billion dollar industry.
> Something that can't be said for inf-sup.

Following this line so far, I'm wondering whether or not engineers' use
of mid-rad in specifications is the same as use of inf-sup in
actual calculations.  If engineers use mid-rad only to specify the
problem, then wouldn't standardization of a decimal-to-binary conversion
between mid-rad and inf-sup, along with standardization of a
corresponding from binary inf-sup to mid-rad, suffice for us?

> > B.
.
.
.

> In terms of interval hardware, mid-rad has an ability to encode an interval
> in much fewer bits than inf-sup. This means more intervals can be stored in
> memory, and bandwith to and from the processors will be better than for
> inf-sup. So this in my view is a strong reason to consider that there will
> someday be a competitive advantage for vendors who wish to support hardware
> implementations of mid-rad over inf-sup.

How crucial is (or will be in the foreseeable future) the storage
issue?

> How this may or may not impact P1788, I'm not sure. But it seems to me
> worth
> looking at.
>
> Nate


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R. Baker Kearfott,    rbk@xxxxxxxxxxxxx   (337) 482-5346 (fax)
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Department of Mathematics, University of Louisiana at Lafayette
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