gusucode.com > 支持向量机工具箱 - LIBSVM OSU_SVM LS_SVM源码程序 > 支持向量机工具箱 - LIBSVM OSU_SVM LS_SVM\stprtool\quadrat\pquad2d.m
function []=pquad2d(A,B,C,plotargs,win,interp) % PQUAD2D plots contour of quadratic function in 2D. % pquad2d(A,B,C,plotargs,win,interp) % % PQUAD2D plots quadratic function in 2D space which is % defined as % x'*A*x + B'*x + C = 0, % % where A is matrix [2x2], B is vector [2x1] and C is real [1x1]. % % The argument plotargs has the same meaning as in Matlab function plot. % The function domain can be restricted by argument % win=[xmin xmax ymin ymax], default values are taken from current % axes. The quadratic function is interpolated by lines and their % number can be controled by the argument interp. % % Input: % A [2x2], B [2x1], C [1x1] coefficients of quadratic function % plotargs [string] see help plot. % win [1x4] function domain, i.e. win=[xmin xmax ymin ymax] % interp [1x1] number of lines used for interpolation. % % See also L2Q2D. % % Statistical Pattern Recognition Toolbox, Vojtech Franc, Vaclav Hlavac % (c) Czech Technical University Prague, http://cmp.felk.cvut.cz % Written Vojtech Franc (diploma thesis) 19.11.1999 % Modifications % 26-June-2001, V.Franc, comments repared. % 24. 6.00 V. Hlavac, comments polished. if nargin < 4, plotargs = ''; end if nargin < 5, win = axis; end if nargin < 6, [x1,y1,x2,y2]=quad2d(A,B,C,win); else [x1,y1,x2,y2]=quad2d(A,B,C,win,interp); end hold on; if length(x1) ~= 0, plot(x1,y1,plotargs); end if length(x2) ~= 0, plot(x2,y2,plotargs); end