Cylinder with top code

Question

Joshua Papworth 2019-3-13

回答： Star Strider 2019-3-13

The code below creates a full cylinder with radius 1 and height 1.

I was wondering what lines 3 and 4 actually do to the cylinder- I don't understand how it changes it into that shape.

figure(5)

[x,y,z] = cylinder([0,1,1,0],100);

z([1,2],:)=0;

z([3,4],:)=1;

mesh(x,y,z)

Answer 1

Star Strider 2019-3-13

Those lines create flat upper and lower surfaces. The upper and lower surfaces otherwise would appear conical.

The easiest way to see that is simply to ‘comment them out’:

figure(5)
[x,y,z] = cylinder([0,1,1,0],100);
% z([1,2],:)=0;
% z([3,4],:)=1;
mesh(x,y,z)

Then restore them to get the desired figure.