Possibilities of using for end loop in code

I want to build an articulated pendulum, let say up to 15 pendulums. Here, I define the first two pendulums as:

x1 = (r1/2)*cos(theta1);

y1 =(r1/2)*sin(theta1);

x2 = (r2/2)*cos(theta2)+ r1*cos(theta1);

y2 = (r2/2)*sin(theta2) + r1*sin(theta1);

y=[x1 0 y1 0 theta1 0 x2 0 y2 0 theta2 0];

but I'm not sure how to write it by using for end loop so that I could build it until 15 pendulums. Also, should there is another way to do it, I would highly appreciated to learn about that. Thanks in advance.

[Dyuman Joshi]

What are the values of theta1, theta2, .....?

And what is the formula/relation for (xn,yn)?

A better idea will be to put data for each pendulum in a row, so that is easy to access -

out=[x1 0 y1 0 theta1 0;
     x2 0 y2 0 theta2 0;
     ...
     xn 0 yn 0 thetan 0]; 

Answer 1

[Chunru]

In MATLAB, you can do it without loop (preferred approach):

theta = [0 10 20 30 50]';        
r     = [9  8  7  6  3]';
y = [(r/2).*cos(theta), (r/2).*sin(theta), zeros(size(theta))]

y = 5×3

4.5000 0 0 -3.3563 -2.1761 0 1.4283 3.1953 0 0.4628 -2.9641 0 1.4474 -0.3936 0