contour.txt

matlab 双坐标轴 参考时请根据需要适当修改

xa=-2:0.2:2;
ya=-2:0.5:2;
[x,y]=meshgrid(xa,ya);
z=x.*exp(-x.^2-y.^2);
[px,py]=gradient(z,xa,ya);
contour(x,y,z);
hold on
quiver(x,y,px,py);
hold off