Re: float problem

["David C. Hoos" <david.c.hoos.sr@ada95.com>]

It is impossible for _any_ computer language or compiler to _not_
round when converting to machine representation to decimal
representation, unless the machine representation is decimal --
something that no modern machine does.  This is because only certain
decimal values are _exactly_ representable in binary.  For example
0.1 is not exactly representable in binary, but values like 0.125, 0.375,
etc. are exactly representable.

The issue, then, is the _degree_ of rounding that is done.
In the case of the Ada type Float, most compilers use that type for
32-bit floating point, while 64-bit floating point is implemented
with the type Long_Float.

----- Original Message ----- 
From: "Jan Prazak" <janp9@gmx.net>
Newsgroups: comp.lang.ada
To: <comp.lang.ada@ada.eu.org>
Sent: Monday, July 08, 2002 3:20 PM
Subject: Re: float problem


> On Sun, 07 Jul 2002 13:08:01 -0100, Frank J. Lhota wrote:
> 
> > The error is small enough to
> > not affect the printed output, where things are rounded to six
> > significant digits, ...
> 
> Thanks, I didn't know that procedure "put" rounds given number. I have
> just started to learn Ada, but I was using Pascal (and a bit Delphi)
> before, where there is no rounding in procedure "write".
> BTW: is it possible to disable the rounding in "put"? Maybe with some
> global boolean variable or someting (maybe a pragma).
> 
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