h0=1;
g=1;
set(gca,'FontSize',18)

c0=sqrt(g*h0);
xmin=-20;
xmax=20;

t_range=0.01:0.5:10.01;
delete video.gif    %have to delete old one so new one shows up
for j=1:length(t_range)
    t=t_range(j);
    
    xL=xmin:0.01:(-c0*t);
    xC=(-c0*t):0.01:(2*c0*t);
    xR=(2*c0*t):0.01:xmax;
    
    hL=h0*ones(size(xL));
    hC=h0/9.*(2-xC./(c0*t)).^2;
    hR=zeros(size(xR));
    
    x=[xL,xC,xR];
    h=[hL,hC,hR];
    
    plot(x,h,'LineWidth',2)
    xlim([-20,20])
    ylim([0,2*h0])
    grid on
    title(['t=',num2str(t_range(j) - 0.01,'%1.1f')])
    ylabel('h')
    xlabel('x')
    pause(0.1)
    gif_add_frame(gcf,'video.gif',1);
end