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Re: Motion to finalise interval literals



On 6/14/2013 7:58 AM, Ned Nedialkov wrote:


Dear All, 

I strongly believe text2interval and interval2text must be present. Below is an example from my experience. 

It is *really annoying* when two package produce output in different formats, when 
everything else is the same. 


I hope the above is convincing that having standardized conversion functions is a must.


Actually, I do not find this convincing.  If you have a program VNODE-LP, that is supposed to work on
various computers and with various underlying pieces of software e.g. FILIB++ and PROFIL,
and VNODE-LP produces different answers (or the same answers but in different formats),
to the extent that it matters to you,
then VNODE-LP was not properly "ported" to these different environments.

In fact, I would expect that VNODE-LP  could extract the inf and sup values from intervals
computed by FILIB++ and PROFIL, and present them in a uniform manner, if the issue were
raised to the appropriate level of concern to the program author.

One could similarly object to things not being
exactly the same if one computer were IEEE754 double compliant and the other used
IEEE754-double-extended, and gave more digits.

I think it would be unreasonable to  insist that the interval library be changed so the results were
printed the same,  although I suppose one could argue, just as one could argue (as essentially
has been done)  that the interval package should decimal arithmetic and hence believes
that 0.1 = 1/10, even on a binary-float machine.


RJF
.