[clean-list] Re: 1.Floating Point Support (clean-list digest)

[Jerzy Karczmarczuk]

Siegfried Gonzi wrote:


> I do not know what you really mean, but rounding errors are
> inavoidable (in everey language); that is my naive assumption.
> 
> How can a programming language active control the rounding errors? 
> A number is rounded up or down.
> 
> But hasn't Clean incorporated the BigNumerical-Library for that
> issues?

Oh, my goodness...
There is a whole huge theory and practice around/behind that...

Perhaps you should have a look on the literature about the
floating point precision, what to do with "hidden bits", etc.

There are nice references here, 

http://cch.loria.fr/documentation/IEEE754/index.html

for example the slides
"What can you learn about Floating-Point Arithmetic in One Hour ?"
by Kahan (who else...):

http://cch.loria.fr/documentation/IEEE754/wkahan/cs267fp.ps

[[of course the fact that I am giving french links is a bit
  accidental, you find such stuff everywhere.]]

A MUST (one of favourite words of the new French generation) is
the article of David Goldberg: "What Every Computer Scientist
Should Know About Floating-Point Arithmetic", published in
Computing Surveys, March 1991, and available on-line
(for example here):

http://www.validgh.com/goldberg/paper.ps

You will bury very deeply your "naive assumptions"...

 
===

BigNums are not *FOR THAT* ! A bazooka to kill flies is OK, but
not very economic.

Jerzy Karczmarczuk
Caen, France