| 1 | ;;; float-sup.el --- define some constants useful for floating point numbers. |
| 2 | |
| 3 | ;; Copyright (C) 1985, 1986, 1987, 2001, 2002, 2003, 2004, 2005, 2006, |
| 4 | ;; 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. |
| 5 | |
| 6 | ;; Maintainer: FSF |
| 7 | ;; Keywords: internal |
| 8 | ;; Package: emacs |
| 9 | |
| 10 | ;; This file is part of GNU Emacs. |
| 11 | |
| 12 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
| 13 | ;; it under the terms of the GNU General Public License as published by |
| 14 | ;; the Free Software Foundation, either version 3 of the License, or |
| 15 | ;; (at your option) any later version. |
| 16 | |
| 17 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | ;; GNU General Public License for more details. |
| 21 | |
| 22 | ;; You should have received a copy of the GNU General Public License |
| 23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
| 24 | |
| 25 | ;;; Commentary: |
| 26 | |
| 27 | ;;; Code: |
| 28 | |
| 29 | ;; Provide an easy hook to tell if we are running with floats or not. |
| 30 | ;; Define pi and e via math-lib calls (much less prone to killer typos). |
| 31 | (defconst float-pi (* 4 (atan 1)) "The value of Pi (3.1415926...).") |
| 32 | (defconst pi float-pi "Obsolete since Emacs-23.3. Use `float-pi' instead.") |
| 33 | |
| 34 | (defconst float-e (exp 1) "The value of e (2.7182818...).") |
| 35 | |
| 36 | (defconst degrees-to-radians (/ float-pi 180.0) |
| 37 | "Degrees to radian conversion constant.") |
| 38 | (defconst radians-to-degrees (/ 180.0 float-pi) |
| 39 | "Radian to degree conversion constant.") |
| 40 | |
| 41 | ;; These expand to a single multiply by a float when byte compiled. |
| 42 | |
| 43 | (defmacro degrees-to-radians (x) |
| 44 | "Convert X from degrees to radians." |
| 45 | (list '* degrees-to-radians x)) |
| 46 | (defmacro radians-to-degrees (x) |
| 47 | "Convert X from radians to degrees." |
| 48 | (list '* radians-to-degrees x)) |
| 49 | |
| 50 | (provide 'lisp-float-type) |
| 51 | |
| 52 | ;;; float-sup.el ends here |