Storing data from a loop

I am struggling to store data from a loop, i need the data so that i am able to plot it. Thanks in advance!

for i=2:50
    i=find((r>=t2n)&(r<t2p));
    Y1=y(i);
    Y2=mean(Y1)
end

Answer 1

[per isakson]

1. Pre-allocate Y1 and Y2
2. Assign to elements of Y1 and Y2
3. Do not change the loop counter, ii, in the loop

The documentation says: Avoid assigning a value to the index variable within the loop statements. The for statement overrides any changes made to index within the loop.

Y1 = nan(1,50);
Y2 = nan(1,50); 
for ii=2:50
    ii=find((r>=t2n)&(r<t2p));
    Y1(ii)=y(ii);
    Y2(ii)=mean(Y1(ii))
end