Drawing multi segments in polar coordinates

I want to draw this segments in matlab

Answer 1

[DGM]

Try something like this

clf
r=[0.5 1]; % minor, major radii
h0=0;   % base height
h=0.25; % height
th0=0;  % start angle (degrees)
th=30;  % included angle (degrees)

tt=linspace(th0,th0+th,10);
hh0=h0*ones(size(tt));
hh=h*ones(size(tt));

% plot the hollow segment
X = [r(1)*cosd([tt; tt]);
     r(2)*cosd([tt; tt]);
     r(1)*cosd(tt)];
Y = [r(1)*sind([tt; tt]);
     r(2)*sind([tt; tt]);
     r(1)*sind(tt)];
Z = [hh0; hh; hh; hh0; hh0];
surf(X,Y,Z,'facecolor','blue'); hold on

% one end face
X = [r(1)*cosd([th0 th0]);
     r(2)*cosd([th0 th0])];
Y = [r(1)*sind([th0 th0]);
     r(2)*sind([th0 th0])];
Z = [h0 h; h0 h];
surf(X,Y,Z,'facecolor','blue');

% the other end face
X = [r(1)*cosd([th th]+th0);
     r(2)*cosd([th th]+th0)];
Y = [r(1)*sind([th th]+th0);
     r(2)*sind([th th]+th0)];
Z = [h0 h; h0 h];
surf(X,Y,Z,'facecolor','blue');

axis equal
axis off

This is probably the long way to do it, but it works. I used to have a good demo for this, but idk what I did with it.

[Elsayed Khodry]

How I can repeat it for n segments like the above picture?

[DGM]

Make a function out of it. The function should just take the parameters needed and plot one segment.

function bluepineapple(r,h,th)
h0=h(1);
h=h(2);
th0=th(1);
th=th(2);

tt=linspace(th0,th0+th,10);
hh0=h0*ones(size(tt));
hh=h*ones(size(tt));

% plot the hollow segment
X = [r(1)*cosd([tt; tt]);
     r(2)*cosd([tt; tt]);
     r(1)*cosd(tt)];
Y = [r(1)*sind([tt; tt]);
     r(2)*sind([tt; tt]);
     r(1)*sind(tt)];
Z = [hh0; hh; hh; hh0; hh0];
surf(X,Y,Z,'facecolor','blue'); hold on

% one end face
X = [r(1)*cosd([th0 th0]);
     r(2)*cosd([th0 th0])];
Y = [r(1)*sind([th0 th0]);
     r(2)*sind([th0 th0])];
Z = [h0 h; h0 h];
surf(X,Y,Z,'facecolor','blue');

% the other end face
X = [r(1)*cosd([th th]+th0);
     r(2)*cosd([th th]+th0)];
Y = [r(1)*sind([th th]+th0);
     r(2)*sind([th th]+th0)];
Z = [h0 h; h0 h];
surf(X,Y,Z,'facecolor','blue');

Then just call the function in a loop, adjusting the starting angle accordingly.

clf
r=[0.5 1];  % minor, major radii
h=[0 0.25]; % base, top height
th=[0 30];  % start, included angles (degrees)
n=6;

clf
for s=1:n
    th(1)=360/n*(s-1);
    bluepineapple(r,h,th);
end
axis equal
axis off