Drawing phase diagram of differential equation with MATLAB dx./dt=y*(4+x^2-y^2) dy./dt=-x(-2-x^2+y^2) Please write the MATLAB phase diagram method of the equation source program!

Drawing phase diagram of differential equation with MATLAB dx./dt=y*(4+x^2-y^2) dy./dt=-x(-2-x^2+y^2) Please write the MATLAB phase diagram method of the equation source program!

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');