function [] = prob_3_3() % PROB_3_3 - % % Written by: % -- % John L. Weatherwax 2005-04-13 % % email: wax@alum.mit.edu % % Please send comments and especially bug reports to the % above email address. % %----- d = 0.001; epsilon = 0.1; k = 0.1; solinit = bvpinit(linspace(d,1,10),@guess,0); sol = bvp4c(@f,@bcs,solinit,[],epsilon,k); p = sol.parameters; xsml = linspace(0,d,10); p0=plot( xsml, p + (10/3)*(p/(0.1+p))*xsml.^2, '-og' ); hold on; p1=plot( sol.x, sol.y(1,:), '-bo' ); p2=plot( sol.x, sol.y(2,:), '-ro' ); grid on; legend( [p1,p2], 'y1', 'y2','Location','NorthWest' ); fprintf( 'p = %g.\n', sol.parameters ); function [ v ] = guess(x) % GUESS - % y = zeros(1,length(x)); yp = y; v = [ y; yp ]; function [res] = bcs(ya,yb,p,epsilon,k) % BCS - % res = [ ya(1)-p; ya(2); yb(1)-1 ]; function [ ode ] = f(x,y,p,epsilon,k) % F - % y(1)=y; y(2)=y' % ode = [ y(2); y(1)/(epsilon*(y(1)+k)) - 2*y(2)/x ];