matlab如何畫螺旋體

d=1;%螺距

r=0.05;?%螺線粗半徑

th=linspace(0,10*pi,361);

ph=linspace(0,2*pi,37);

[t?p]=meshgrid(th,ph);

x=(R+r*cos(p)).*cos(t);

y=(R+r*cos(p)).*sin(t);

z=d*t/(2*pi)+r*sin(p);

surf(x,y,z,'edgecolor','none','facecolor','b','facealpha',0.5);hold?on

surf(x,-y,z,'edgecolor','none','facecolor','g','facealpha',0.5);hold?off

axis?equal;

xlabel('X');

ylabel('Y');

zlabel('Z');