Subject: Re: Q: Degree instead of Radian?
From: Erik Naggum <>
Date: 15 Dec 2000 00:12:42 +0000
Newsgroups: comp.lang.lisp
Message-ID: <>

* "Pierre R. Mai" <>
| That should make it both more readable, and less error-prone.  If the
| need for speed is even greater you could consider declaring rad-to-deg
| inline (or using compiler-macros for the same effect on
| implementations like Franz' ACL) and/or (after careful analysis!)
| reducing safety to 0.

  I would have suggested a compiler macro on the trigonometric functions
  that looked for a conversion of the argument from degrees to radians,
  say with a form like (sin (degrees ...)), to do the computation and
  conversion with as little loss of precision as possible.  This may be
  done only if you shadow the symbol in new package, since sin (etc) are
  in the common-lisp package and anyone else doing a similar compiler-
  macro would mess with yours.

  The United States of America, soon a Bush league world power.  Yeee-haw!