Generating a cylindrical cluster

I have created a 3D cluster and assigned values to represent a sandstone as attaced (3dlattice). Now, I want to create a cylinder to resemble a core and randomly assign two particular values across the cylinder. I am working with the below code but couldn't achieve my goal. I would appreciate, if you could guide me on the correct path?

n=10000; % number of points that you want

center = [20 ,20]; % center coordinates of the circle [x0,y0]

radius = 12.5; % radius of the circle

angle = 2*pi*rand(n,1);

r = radius*sqrt(rand(n,1));

X = round(r.*cos(angle)+ center(1));

Y = round(r.*sin(angle)+ center(2));

Z=round(60*sqrt(rand(n,1)));

scatter3(X,Y,Z);

Thank you.