;;; PLT Scheme Science Collection ;;; machine.ss ;;; Copyright (c) 2004 M. Douglas Williams ;;; ;;; This library is free software; you can redistribute it and/or ;;; modify it under the terms of the GNU Lesser General Public ;;; License as published by the Free Software Foundation; either ;;; version 2.1 of the License, or (at your option) any later version. ;;; ;;; This library is distributed in the hope that it will be useful, ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ;;; Lesser General Public License for more details. ;;; ;;; You should have received a copy of the GNU Lesser General Public ;;; License along with this library; if not, write to the Free ;;; Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA ;;; 02111-1307 USA. ;;; ;;; ------------------------------------------------------------------- ;;; ;;; This code is based on the machine precision and limits constants ;;; in the GNU Scientific Library (GSL), which is also licensed under ;;; the GPL. ;;; ;;; Version Date Description ;;; 0.1.0 08/14/04 This is the initial release of the machine ;;; constants ported from GSL. (Doug Williams) ;;; 1.0.0 09/20/04 Marked as ready for Release 1.0 (Doug ;;; Williams) (module machine mzscheme (provide (all-defined)) ;; Magic constants; mostly for the benefit of the implementation (define double-epsilon 2.2204460492503131e-16) (define sqrt-double-epsilon 1.4901161193847656e-08) (define root3-double-epsilon 6.0554544523933429e-06) (define root4-double-epsilon 1.2207031250000000e-04) (define root5-double-epsilon 7.4009597974140505e-04) (define root6-double-epsilon 2.4607833005759251e-03) (define log-double-epsilon -3.6043653389117154e+01) (define double-min 2.2250738585072014e-308) (define sqrt-double-min 1.4916681462400413e-154) (define root3-double-min 2.8126442852362996e-103) (define root4-double-min 1.2213386697554620e-77) (define root5-double-min 2.9476022969691763e-62) (define root6-double-min 5.3034368905798218e-52) (define log-double-min -7.0839641853226408e+02) (define double-max 1.7976931348623157e+308) (define sqrt-double-max 1.3407807929942596e+154) (define root3-double-max 5.6438030941222897e+102) (define root4-double-max 1.1579208923731620e+77) (define root5-double-max 4.4765466227572707e+61) (define root6-double-max 2.3756689782295612e+51) (define log-double-max 7.0978271289338397e+02) ;; I'm not sure about the next ones - MDW. ;; a little internal backwards compatibility (define machine-eps double-epsilon) ;; Here are constants related to or derived from ;; machine constants. These are not to be confused with ;; the constants that define various precision levels ;; for the precision/error system. ;; ;; This information is determined at configure time ;; and is platform dependent. Edit at your own risk. ;; machine precision constants ;; (define machine-eps 1.0e-15) (define sqrt-machine-eps 3.2e-08) (define root3-machine-eps 1.0e-05) (define root4-machine-eps 0.000178) (define root5-machine-eps 0.00100) (define root6-machine-eps 0.00316) (define log-machine-eps -34.54) )