Re: floats and intervals, constants, 0.1, 1e400 and Inf

["Chenyi Hu" <chu@xxxxxxx>]

Yes, Arnold, you are very correct. What I mean was in representing data and results of application. It is also helpful for algorithm development (for example, interval least-squares approximation and others, see  http://
springer.com/978-1-84800-325-5). 

The C++ package that we developed and used is available at http://www.cs.uca.edu/interval/ It is based on the Interval BLAS Standard available at http://www.netlib.org/blas/blast-forum/chapter5.pdf

I would also like to clarify that I am not insist to include mid-rad arithmetic in the standard. A conversion utility routine would work fine for me. 

Chenyi

>>> Arnold Neumaier <Arnold.Neumaier@xxxxxxxxxxxx> 11/12/2008 1:42 AM >>>
Chenyi Hu schrieb:
 > We have applied midpoint-radius representations in recent work.
 > It certainly has its advantage in handling uncertainty.

Could you please state the computational advantages compared
to the inf-sup representation rather than only asserting
their existence?

Clearly the representation is useful for interpreting data and results 
of an application. But this only affects conversion from and to text,
not the arithmetic with mid-rad intervals.

Which package do you use for mid-rad interval arithmetic?


Arnold Neumaier



 >
 >>>> "Svetoslav Markov" <smarkov@xxxxxxxxxx> 11/11/2008 2:04 AM >>>
 > On 10 Nov 2008 at 13:02, Arnold Neumaier wrote:
 >
 >> Though briefly discussed, I think nobody has shown strong emotions for
 >> satandardizing mdpoint-radius interval representations.
 >> I advocate against it.
 >>
 >
 > I should like to declare myself as a strong supporter of
 > midpoint-radius interval representations.
 >
 >  Svetoslav Markov
 >
 >