vdp_2.m

This the mathematical computational method of step-vary Gill method.

function dy = vdp_2(t,y)
% 为题2的微分方程
if t>1 
    dy = [(-1.06*y(1)-2.85*y(2)-2.25+2)/0.1;
        y(1)];
else
    dy = [(-1.06*y(1)-2.85*y(2)-2.25+4.5*t+3*t^2)/0.1;
        y(1)];
end