;;; PLT Scheme Science Collection ;;; random-distributions/bivariate-gaussian-graphics.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 implements graphics for bivariate gaussian distributions. ;;; ;;; Version Date Description ;;; 0.1.0 08/07/04 This is the initial release of the bivariate ;;; gaussian distribution graphics routines. (Doug ;;; Williams) ;;; 1.0.0 09/28/04 Added contracts for functions. Marked as ready ;;; for Release 1.0. (Doug Williams) (module bivariate-gaussian-graphics mzscheme (require (lib "contract.ss")) (provide/contract (bivariate-gaussian-plot (-> (>=/c 0.0) (>=/c 0.0) (real-in -1.0 1.0) any))) (require "bivariate-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 (bivariate-gaussian-plot sigma-x sigma-y rho) (plot3d (surface (lambda (x y) (bivariate-gaussian-pdf x y sigma-x sigma-y rho))) (x-min (* -3 sigma-x)) (x-max (* 3 sigma-x)) (y-min (* -3 sigma-y)) (y-max (* 3 sigma-y)) (z-min 0) (z-max 1) (z-label "Density") (title "Bivariate Gaussian Distribution"))) )