**Subject:** Re: bc (1)

**To:** None *<banshee@gabriella.resort.com>*

**From:** Phil Nelson *<phil@cs.wwu.edu>*

**List:** current-users

**Date:** 06/21/1996 10:19:15
>does someone familiar with this utility know why it chooses to recode
>series approximations for sin(), cos(), atan() rather than calling the
>(hopefully) functional and accurate library ones?
>
>i was just grousing that it lacks acos() and asin(), and was slightly
>horrified to see what its doing.
yes, I know. :) bc is an arbitrary precision calculator language.
Therefore, one must implement arbitrary precision versions of the
trig functions. For example, using the C library one would not get
accurate results for:
scale = 200; 4*a(1);
(which, by the way, prints the first 200 digits after the decimal
point of PI.)
If you write a faster algorithm for computing them accurately to
an arbitrary precision, or write acos() and asin(), please send them
to me. I'll include them in the next version of GNU bc.
--
Phil Nelson NetBSD: http://www.netbsd.org
e-mail: phil@cs.wwu.edu LPF: http://www.lpf.org
http://www.cs.wwu.edu/~phil !gifs: http://www.lpf.org/Patent/Gif/Gif.html