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Re: Avoiding roundoff errors in calculations?

• To: Tim Bray <tbray@t...>,"Roger L. Costello" <costello@m...>
• Subject: Re: Avoiding roundoff errors in calculations?
• From: Don Bate <donbate@i...>
• Date: Fri, 29 Aug 2003 16:47:37 -0500
• Cc: xml-dev@l...
• In-reply-to: <3F4FAFFF.1060900@t...>
• References: <3F4FA206.5E2367A2@m...> <3F4FAFFF.1060900@t...>

It occurs in financial calculations all the time. Anything that uses 
decimal calculations instead of binary calculations runs into the 
problem that many decimal numbers (such as 0.1) can't be represented 
exactly with a binary floating point number no matter how many bits 
of binary precision you use. That's why many use high or infinite 
precision decimal arithmetic and don't worry about binary floating 
point inaccuracies. At least that way they don't have to be a math 
expert to figure out whether it's safe or not and different 
implementations will come up with the same answer.

Don Bate

At 12:56 PM -0700 8/29/03, Tim Bray wrote:
>Roger L. Costello wrote:
>
>>What are your thoughts on this?  What techniques do people use to avoid
>>introducing roundoff errors?  /Roger
>
>Use FORTRAN, it supports REAL numbers, it says so right in the syntax :)
>
>I'm curious; what applications require more precision than IEEE double? -Tim
>
>
>
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-- 
Don Bate               | Specializing in Consulting and Mentoring in
Bate Consulting, Inc   | Object-Oriented Technologies,
                        | Software Architecture, and Software Process
(972) 618-0208 voice
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• References:
  • Avoiding roundoff errors in calculations?
    • From: "Roger L. Costello" <costello@m...>
  • Re: Avoiding roundoff errors in calculations?
    • From: Tim Bray <tbray@t...>

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