function dy = fun2(t,y)dy=zeros(2,1);%%%设u(t),v(t)为0c=2;a=2;d=3;b=4;%设y(1)=x,y(2)=y,dy(1)=x',dy(2)=y'dy(1)=-cy(1)y(2)-ay(1);dy(2)=-dy(1)y(2)-by(2);
endtspan=[0 10];y0=[2 2];%初值[t,y]=ode45('fun2',tspan,y0);plot(y(:,1),y(:,2));