function phasemovie1
    clear; clf;
    A = [-5, 1; -18, 1];
    [a,b]=solve('-5*x+y=0', '-18*x+y=0');
    a=double(a);b=double(b);
    hold on
    axis([a-5,a+5,b-5,b+5])
    [x0,y0]=ginput(1);
    tmax=10;
    [T,Z]=ode45(@ff,[0,tmax],[x0,y0]);
    [T1,Z1]=ode45(@ff,[0,-tmax],[x0,y0]);
    A1=Z1(:,1);B1=Z1(:,2);
    A2=A1(length(A1):-1:2);
    B2=B1(length(B1):-1:2);
    A3=[A2;Z(:,1)];
    B=[B2;Z(:,2)];
    x=[];y=[];
        for k=1:length(A3)
            x=[x,A3(k)];
            y=[y,B(k)];
            plot(x,y)
            M(k)=getframe;
        end
    movie(M,2)    
    function z=ff(t,y)
        z=A*y;
    end
end