Re: Trig question: just 14 bits?

> -----Original Message-----
> From: swiftx-bounce_at_forth.com [mailto:swiftx-bounce_at_forth.com]On Behalf
> Of Noel Henson
> Sent: Tuesday, March 28, 2006 9:23 AM
> To: swiftx_at_forth.com
> Subject: [swiftx] Trig question: just 14 bits?
>
>
> Why are the angles in the trig functions represented by only 14 bits? Why
> not 16 or 30?

In the past, for various applications, we've done 15, 30, and 31-bit
versions. We might have them around somewhere. It's useful to keep the
sign bit free. Beyond that, it's just a matter of how many bits you need,
and a balance between the number of terms in the approximation and the time
you can spend in the calculation.

The algorithms are given in Hart, John F., et al, Computer Approximations,
Krieger Publishing Co. Inc., P.O. Box 9542, Melbourne FL 32902-9542.
Telephone (305) 724-9542

Cheers,
Elizabeth

============================================
Elizabeth D. Rather
FORTH Inc. +1 310-491-3356
5155 W. Rosecrans Ave. Fax: +1 310-978-9454
Suite 1018 (US & Canada) 800-55-FORTH
Hawthorne, CA 90250
http://www.forth.com

"Forth-based products and Services for real-time applications since 1973."
============================================

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Received on Tue Mar 28 2006 - 10:05:08 PST