[求助]怎样设置才可以让我的图形只绘制上面的部分
向高手讨教:我的程序:
a1=linspace(0,2*pi,1000);
u=linspace(0,1,500);
syms a1 a2 t u;
a2=3*a1/4+0.08*cos(3*a1+3*pi/2);
g=0.75-0.24*sin(3*a1+3*pi/2);
f=atan(t);
k1=compose(f,g);
x1=54*cos(a1).*sin(k1);
y1=54*sin(a1).*sin(k1);
z1=54*cos(k1);
x11=u*x1;
y11=u*y1;
z11=u*z1;
ezsurf(x11,y11,z11);
绘制出的图形: