Hi Tijs,
I understand that you wish to plot a cylindrical surface with variable height on linear basis. To achieve this, you can try to use the 'cylinder' function from the MathWorks Documentation. To make the height of cylinder (variable 'Z') can be made variable by multiplying with a triangle matrix.
Find below an example to do so -
% Define radius of Cylinder
r = 1;
% Define number of points
N = 100;
% Get X,Y,Z coordinates
[X,Y,Z] = cylinder(r,N);
m = N/2;
u = [zeros(1,m) 1 zeros(1,m); zeros(m-1,1) flip(tril(ones(m-1))') ones(m-1,1) (triu(ones(m-1))') zeros(m-1,1)];
% Make triangle matrix
h = [u;ones(1,2*m+1);flip(u)];
% Multiply Z to vary height linearly and devide my m to scale
Z = Z*h/m;
% Plot the surface for upper half
surf(X,Y,Z);
hold on;
% Plot surface for lower half
surf(X,Y,-1*Z);
% Change view
view([32 42]);
