m=30; z=1.2*(0:m)/m; r=ones(size(z)); theta=(0:m)/m*pi*2; x1=r'*cos(theta); y1=r'*sin(theta); z1=z'*ones(1,m+1); x=(-m:2:m)/m; x2=x'*ones(1,m+1); y2=r'*cos(theta); z2=r'*sin(theta); surf(x1,y1,z1); axis equal,axis off; hold on; surf(x2,y2,z2); axis equal,axis off; title('两个圆柱体相交图形'); hold off;