How can I truncate a prolate spheroid?

I first generated a prolate spheroid through:

[x y z] = sphere;
  x = x;
  y = y;
  z = 2*z;
  surf(x,y,z), axis equal

I need to truncate the prolate spheroid at one end. What is a simple way of doing this?

Cheers,

Nic

Answer 1

[Image Analyst]

Try using logical indexing to set the top flat:

[x y z] = sphere(100);
x = x;
y = y;
z = 2*z;
highZ = z > 1;
x(highZ) = 0;
y(highZ) = 0;
z(highZ) = 1;
surf(x,y,z);
axis equal

[Nicholas]

Thanks very much - a simple and effective solution.

Cheers

Nic