From: Nick Roberts <nickroberts@callnetuk.com>
Subject: Re: fixed type (delta) in ada
Date: 1999/11/28
Date: 1999-11-28T00:00:00+00:00 [thread overview]
Message-ID: <384118EF.911A1ABB@callnetuk.com> (raw)
In-Reply-To: 383f6dbb.22609744@news.tstonramp.com
Nap wrote:
>
> does anyone know why mutiplication between fixed type in ada produce a
> big round off error?
> ...
Do you want the short answer or the long answer, Nap?
The short version of the long answer is: the 'small' chosen for the type
'money' will be a power of two (e.g. 1/128); 0.20 will therefore not
have an exact representation when converted to the type 'money'; this
inexact representation of 0.20 will therefore produce an inexact result
after multiplication.
The short version of the short answer is: use a decimal type instead of
a fixed type (example follows).
type Money is delta 0.01 digits 11;
Problem solved.
--
Nick Roberts
http://www.adapower.com/lab/adaos
Always call for the professionals. (If they don't help, call for me ;-)
next prev parent reply other threads:[~1999-11-28 0:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-11-27 0:00 fixed type (delta) in ada Nap
1999-11-26 0:00 ` Al Christians
1999-11-27 0:00 ` fixed type (delta) in ada and GNAT bug David C. Hoos, Sr.
1999-11-28 0:00 ` Nick Roberts [this message]
1999-11-30 0:00 ` fixed type (delta) in ada Simon Wright
1999-11-28 0:00 ` Robert Dewar
1999-11-27 0:00 ` Al Christians
1999-11-28 0:00 ` Florian Weimer
1999-11-28 0:00 ` Al Christians
1999-11-29 0:00 ` Preben Randhol
1999-11-29 0:00 ` Al Christians
1999-11-29 0:00 ` Preben Randhol
1999-11-28 0:00 ` Preben Randhol
1999-11-29 0:00 ` Robert Dewar
1999-11-29 0:00 ` Al Christians
1999-11-29 0:00 ` Lutz Donnerhacke
1999-11-29 0:00 ` Preben Randhol
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