function fig232 clf nx=200; x=linspace(-10,30,nx); % get(gcf) %set(gcf,'Position', [1948 1118 573 199]); set(gcf,'Position', [990 937 613 186]); ep=1; t=1; for ix=1:nx s1 = erfc( 0.5*(x(ix)-t)/sqrt(ep*t) ); s2 = erfc( -0.5*x(ix)/sqrt(ep*t) ); k = s1*exp(- 0.5*(x(ix)-0.5*t)/ep )/s2; u1(ix) = k/(1+k); xb = (x(ix)-0.5*t)/ep; ua1(ix) = exp(-0.5*xb)/(1+exp(-0.5*xb)); end; t=15; for ix=1:nx s1 = erfc( 0.5*(x(ix)-t)/sqrt(ep*t) ); s2 = erfc( -0.5*x(ix)/sqrt(ep*t) ); k = s1*exp(- 0.5*(x(ix)-0.5*t)/ep )/s2; u2(ix) = k/(1+k); xb = (x(ix)-0.5*t)/ep; ua2(ix) = exp(-0.5*xb)/(1+exp(-0.5*xb)); end; t=30; for ix=1:nx s1 = erfc( 0.5*(x(ix)-t)/sqrt(ep*t) ); s2 = erfc( -0.5*x(ix)/sqrt(ep*t) ); k = s1*exp(- 0.5*(x(ix)-0.5*t)/ep )/s2; u3(ix) = k/(1+k); xb = (x(ix)-0.5*t)/ep; ua3(ix) = exp(-0.5*xb)/(1+exp(-0.5*xb)); end; plot(x,u1,'--','Linewidth',1) hold on plot(x,ua1,'-','Linewidth',1) plot(x,u2,'--','Linewidth',1) plot(x,ua2,'-','Linewidth',1) plot(x,u3,'--','Linewidth',1) plot(x,ua3,'-','Linewidth',1) % ep=1 text(-5.5,0.7,'t = 1','FontSize',14,'FontWeight','bold') text(2.05,0.6,'t = 15','FontSize',14,'FontWeight','bold') text(10.4,0.5,'t = 30','FontSize',14,'FontWeight','bold') say=['\epsilon = ',num2str(ep)]; text(26,0.88,say,'FontSize',14,'FontWeight','bold') % ep=0.1 %text(-3.3,0.7,'t = 1','FontSize',14,'FontWeight','bold') %text(3.3,0.6,'t = 15','FontSize',14,'FontWeight','bold') %text(10.8,0.5,'t = 30','FontSize',14,'FontWeight','bold') %say=['\epsilon = ',num2str(ep)]; %text(24,0.88,say,'FontSize',14,'FontWeight','bold') box on grid on axis([-10 30 -0.05 1.05]) %loc='NorthWest'; loc='East'; xlabel('x-axis','FontSize',14,'FontWeight','bold') ylabel('Solution','FontSize',14,'FontWeight','bold') set(gca,'FontSize',14); legend(' Exact',' Asymptotic','Location',loc); set(findobj(gcf,'tag','legend'),'FontSize',14);