Question

如何用matlab画4条双y轴的图，2条以左边y轴为准，2条以右边y轴为准

为什么我用plotyy画出的图，右边y轴数据有重合

Answer 1

假设你的y1 y3用左边的坐标轴，y2,y4用右边的坐标轴：

x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);
y3 = y1+40;
y4 = y2+0.3;
figure;
hold on;
[AX,h1,h2] = plotyy(x,y1,x,y2,'plot');
[~,h3,h4] = plotyy(x,y3,x,y4,'plot');
set(h1,'LineStyle','--','Color','r');
set(h2,'LineStyle',':','Color','k');