Indexing and Iteration issues

Input:

for j=1:NS
tsr(j)=((r(j)*rot)/v); %TSR
end

For loop iteration

X(j) requires tsr(j) and a(j).

Both X(j) and a(j) changes every loop.

Before, I use X1(i-1), X2 (i-1).

After receiving suggestions from this forum to use indexing instead, I revised the code using indexing (still a newbie ^^,)

Any idea on how to approach this? It seems I have to deal with X(j,i-1) where j, indexes to 20 variables (equal to X1,X2, X20) and i has something to do with iteration.

Kind regards,

Wes

[Stephen23]

Earlier question:

https://www.mathworks.com/matlabcentral/answers/336984-i-need-to-code-a1-a2-a3-0-any-idea-how-to-do-this-i-ve-read-about-deal-but-it-seems-too-long

[migs]

I followed that sir! the next problem is the indexing and the iteration part. since the variables within the iteration loop have to be indexed as well, hence the confusion.

[migs]

for instance, phi is within the iteration loop. instead of phi1(i-1), phi2(i-1), phi has to be indexed. the problem now moves on to the iteration procedure. could I use two for loops? I'm wondering what will be their respective index will look like.

[Greg Dionne]

Since you're new to MATLAB,

https://www.mathworks.com/videos/working-with-arrays-in-matlab-69022.html

[Stephen23]

Since you are new to MATLAB, you should do the introductory tutorials (which are highly recommended for all beginners, and they introduce indexing:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

https://www.mathworks.com/videos/getting-started-with-matlab-68985.html

Remember to read the MATLAB documentation instead of guessing how it works:

https://www.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html

https://www.mathworks.com/help/matlab/math/matrix-indexing.html

And also read this:

https://www.mathworks.com/matlabcentral/answers/228557-experts-of-matlab-how-did-you-learn-any-advice-for-beginner-intermediate-users