用matlab软件的mershgrid函数绘制双叶双曲面

[x y z]=meshgrid(-20:2:20);

v=x.^2/25+y.^2/36-z.^2/16+1;

p=isosurface(x,y,z,v,0);

patch(p,'edgecolor','r','facecolor','r','facealpha',0.2);

view(