箭头图可以用quiver 二维箭头图函数quiver3 三维箭头图函数绘制
[xx,yy]=meshgrid(-1:0.5:1);zz=-1*ones(size(xx));u = yy + 1;v = zeros(size(xx));w=-1*ones(size(xx));quiver3(xx,yy,zz,u,v,w)
