Store values from a for loop into a matrix

Hello all, if anyone could possibly help me I would greatly appreciate it. I am attempting to store values calculated in a for loop in a matrix. I have already tried to preallocate arrays and create an empty matrix but just cant seem to get it to work.

The matrix would be [65x3] because there are 3 conditions and 65 participants. The for loop calculates one condition from one participant at a time.

for  RARs = zeros(65, 3)
    i = 1:65;
    
RARatio = AUC/RA;
disp(RARatio)

% RAR Matrix
RARmat(RARs, :) = RARatio;
end 

Thank you in advance!

Answer 1

[madhan ravi]

RARmat = zeros(65, 3)
for ii = 1:65
    RARatio = AUC/RA;
    disp(RARatio)
    % RAR Matrix
    RARmat(ii, :) = RARatio;
end

[Jo E.]

Thank you so much!! That definitely works!

Follow up question: Is there any way to qualify that every third iteration of the for loop starts a new row?

[madhan ravi]

ii = 3:3:65

[Jo E.]

Not quite working. But thank you anyway!

[madhan ravi]

What’s not working ? It’s always a good idea to illustrate of what you’re describing, so that it’s easy for people to answer.

[madhan ravi]

Jo E. comments:

I attached a picture of what is coming up when I added this code

ii = 3:3:65

What I am actually looking to do is that each participant has 1 row of 3 columns meaning that 3 itirations of the loop will fill the first row across 3 colums and the 4th itiration will start a new row.

Thank you for the help.

[madhan ravi]

Please don't keep adding answers just to make a comment. Use Comment on this Answer instead.

Perhaps you just want:

ii = 1:3:65

Even if the above doesn't do what you want , you need to show how your expected result should look like with an explicit example.

[Jo E.]

I have attached a photo of what I am looking to be populated in the matrix. After 6 itirations of the loop I will need 2 rows of 3 conditions. I hope that clarifies what I am asking.

[madhan ravi]

You keep on changing your question in each comment. Your original question was how to store values in each iteration. Attach your data as .mat file.

[Jo E.]

Yes and you answered it wonderfully. I asked the follow up question of how to store values of each itiration in a new row after the 3rd iteration. Thank you for your help thus far.

[madhan ravi]

You would be better off starting a new question (also link this thread to that question), so that you get a help soon.

[Jo E.]

Will do. Thank you for your help.