
 clf;
 x=linspace(0,20,400);
 hold on;
 for i=1:7
     %y=max(0,1-i/7 - i*x/140);
     y=(1-i/7)*cos(x/20);
     plot(x,y,'r-','linewidth', 2);
 end
 hold off;

        axis([0,20,0,1])
        set(gca,'FontSize',18); %% set the font of tick label
        xlabel('x, Lagrangian coordinate', 'fontsize', 20);
        ylabel(' f(x,t)', 'fontsize', 20);

        print('-deps', 'regress3.eps')

