Which loops and which co-ordinate system can I use to automate this example of a truss structure

Question

I am completely new to matlab and can't seem to get an if loop to work. For example if Ln > k , plot point i(n-1) to i(n). How would I automatically assign the correct row or column vectors to i(n)?

Here is a diagram of what I'm wanting

What I want to achieve is connect i(0) to i(1) to ... i(n-1) to i(n).

I also am a bit confused at which co-ordinate system to use? I thought it would be easy to use a polar co-ordinate system. Defining a distance and angle from point i(o) and then doing the same from point i(1) but from what I could find, it is necessary to convert back to a cartesian co-ordinate system.

Once I am comfortable with this section I am confident I can take on the next steps, and develop a full solution to my problem. If you are interested in what I am trying to achieve, here's a link

[PLEASE NOTE] In that question I linked to, I was told I made a mess of it. I'm sorry if this question is also not clear. I really have spent the time to make it as clear as possible. I find it hard to express myself sometimes.

Answer 1

For coordinate system, you can use complex numbers as a simple way of working within a 1-D matrix. Otherwise, I'm struggling to understand what you are trying to accomplish. You should at least try to show some code as we will be in a better position to guide you.

There are a bunch of ways you can execute your problem. without getting into details, you do the following:

n = 1
L(1) = ...
point(1) = ...

while (L(n) < k)
    n = n+1;       
    L(n) = L(n-1)*sin(alpha)/sin(alpha+theta);
    point(n) = ...
end

plot(point(1:n));