🚀 go-pugleaf

On 20 Jul 1998 01:14:17 GMT, Michael Zarlenga <zarlenga@conan.ids.net> wrote:
>Hackman ("hacker(nospam)"@jump.nospam.net) wrote:
>: > > GWBASIC uses Microsoft storage for doubles and longs, and not IEEE and
>: > > yes, there is some GREAT rounding errors.
>
>1. Inexactness errors occur with ALL floating point formats, including
>   IEEE S and T.  (An inexactness error is the inability of a series
>   of fractions to accurately represent a real number - all finite-
>   length floating point formats suffer from this.  This is sometimes
>   [incorrectly] referred to as "roudning" error)
>
>2. While I'm unfamiliar with what exactly the "Microsoft" format is,
>   the most inaccurate formats I've ever seen (VAX D, F or G floats,
>   I forget which) have their first digit errors somewhere around the
>   8th (for 32-bit floats) or 15th (64-bit floats) significant digit.
>
>For the vast majority of applications, that amount of error is
>irrelevant.

We are talking about a specific application where it may be relevant.  
However, we can't find out because the code and algorithms are secret,
written by someone who may not understand the possibility.  In my post,
it was correctly a rounding error, as I was talking about adding up lots of
numbers.  In the case of Earl's program, we don't know what he was doing,
whether it was a table lookup or some sort of calculus solving.  Either
way, we don't have any way to verify his program, other than trying to
find a set of data that demonstrably doesn't work.  (And of course, I can't
even do that, not being among the people he will share the program with).
The problem with that sort of "QA" is that we might not hit on the data.  
I'm sure you know that, but does Earl?  If he was using some sort of 
standard libraries or functions that are known to correctly handle the 
problems, he could at least let us know what those are.  As it is, it 
just sounds like he took an amateur GWBASIC program and "translated" 
it to C.  This could mean a less-than-amateur C program.  Comparing the 
output to other programs doesn't mean much, since they could all be wrong.

>
>--
>-- Mike Zarlenga
>   finger zarlenga@conan.ids.net  for PGP public key
>
>   "I'd be happy to give him [oral sex] just to thank him 
>    for keeping abortion legal."  "[I was] quite willing to 
>    let myself be ravished [by President Clinton]."
>             Nina Burleigh, ex-White House correspondent for Time,
>             another member of the "objective" mainstream media

I think the leader of the free world _should_ be a stud-puppie.

jg
-- 
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