用matlab画微分方程的相图

clear;clc


[x,y]=meshgrid(linspace(-5,5));


streamslice(x,y,y.*(4+x.^2-y.^2),-x.*(-2-x.^2+y.^2));
xlabel('x');ylabel('y');

clear;clc

[x,y]=meshgrid(linspace(-5,5));
streamslice(x,y,y.*(4+x.^2-y.^2),-x.*(-2-x.^2+y.^2),'noarrows');
xlabel('x');ylabel('y');