How can I put these subplots into a for loop?

Hello,

I have 1000 points of data (NumKey) I would like to divide into 10 different suplots each showing 100 points of the data. Every other data point is a random number which is why they are markered differently('*' being a random number). I started doing it manually, but am trying to figure out how to make it into a for loop.

I get a bit confused with nested for loops, so I would appreciate any advice.

Thank you in advance!

ntrials=1:100:1000;

figure;

subplot(10,1,1)
ntrials=1:numel(NumKey);
plot(ntrials(1:2:100),NumKey(1:2:100),'o');
hold on
plot(ntrials(2:2:100),NumKey(2:2:100),'*');
yticks([1 2 3 4]);

subplot(10,1,2)
ntrials=1:numel(NumKey);
plot(ntrials(101:2:200),NumKey(101:2:200),'o');
hold on
plot(ntrials(102:2:200),NumKey(102:2:200),'*');
yticks([1 2 3 4]);  

Answer 1

[Geoff Hayes]

Maria - for each of your two blocks of code, look at each line and ask yourself "what is different?" The part that is different will be controlled by your iterating parameter. The trick is finding the general term for the sequence (the part that is different for each of your subplots). In our case, the sequence is

code               iteration              code dependent upon k
============       =========              =========================
1:2:100            k = 1        ==>       1 + 0 * 100 : 2 : 1 * 100
101:2:200          k = 2        ==>       1 + 1 * 100 : 2 : 2 * 100
201:2:300          k = 3        ==>       1 + 2 * 100 : 2 : 3 : 100
...

                   k                      1 + (k - 1) * 100 : 2 : k * 100

And so your code could become

ntrials=1:numel(NumKey);
for k = 1:10
    subplot(10,1,k); % kth subplot
    plot(ntrials((1 + (k-1)*100):2:k * 100), NumKey((1 + (k-1)*100):2:k * 100),'o');
    hold on
    plot(ntrials((2 + (k-1)*100):2:k * 100), NumKey((2 + (k-1)*100):2:k * 100),'*');
    yticks([1 2 3 4]);
end

[Maria Y]

Hi Geoff,

Thanks so much for your detailed explanation. I'm very new to Matlab so having it broken down like that is very helpful. I"ll try to think of for loops in these terms going forward.

Thanks again!

Maria