#lang scheme/base ;;; PLT Scheme Science Collection ;;; random-distributions/gaussian-graphics.ss ;;; Copyright (c) 2004-2008 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 implements graphics for Gaussian distributions. ;;; ;;; Version Date Description ;;; 0.1.0 08/07/04 This is the initial release of the Guassian ;;; distribution graphics routines. (Doug Williams) ;;; 1.0.0 09/28/04 Added contracts for functions. Marked as ready ;;; for Release 1.0. (Doug Williams) ;;; 2.0.0 11/19/07 Changed calls to unchecked versions. ;;; (Doug Williams) ;;; 3.0.0 06/09/08 Changes required for V4.0 (Doug Williams) ;;; 3.0.1 07/01/08 Changed x axis label. (Doug Williams) (require (lib "contract.ss")) (provide/contract (gaussian-plot (-> real? (>=/c 0.0) any)) (unit-gaussian-plot (-> any))) (require "gaussian.ss") (require (lib "plot.ss" "plot")) ;;; gaussian-plot: real x real -> void ;;; Plot the pdf and cdf for a gaussian distribution with the given ;;; mean and standard deviation. The x axis range is +/- three sigma ;;; around the mean. (define (gaussian-plot mu sigma) (plot (mix (line (lambda (x) (unchecked-gaussian-pdf x mu sigma)) (color 'red)) (line (lambda (x) (unchecked-gaussian-cdf x mu sigma)) (color 'blue))) (x-min (+ mu (* -3 sigma))) (x-max (+ mu (* 3 sigma))) (x-label "X") (y-min 0) (y-max 1) (y-label "Density") (title "Gaussian Distribution"))) ;;; unit-gaussian-plot: -> void ;;; Plot the pdf and cdf for a unit gaussian distribution (standard ;;; normal distribution). The x axis range is +/- three. (define (unit-gaussian-plot) (plot (mix (line unchecked-unit-gaussian-pdf (color 'red)) (line unchecked-unit-gaussian-cdf (color 'blue))) (x-min -3) (x-max 3) (x-label "X") (y-min 0) (y-max 1) (y-label "Density") (title "Unit Gaussian Distribution")))