如果是画三维曲线用 plot3：
t = 0:pi/50:10*pi;st = sin(t);ct = cos(t);figureplot3(st,ct,t)
如果是画曲面，用 surf:
[X,Y] = meshgrid(-2:0.2:2,-2:0.2:2);Z = X.*exp(-X.^2 - Y.^2);figuresurf(X,Y,Z)
