# How can I return the values of a loop

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zaxtronix on 12 May 2016
Commented: Andrei Bobrov on 13 May 2016
I want to return the entire values of k matrice but I only end up with values from the last row.
for i = 1:5,
j = 0:i;
k = i.^2 + i*j + j.^2
end

Felix Lauwaert on 12 May 2016
Edited: Felix Lauwaert on 12 May 2016
You are computing k once for each value of i and overwriting it. If I understand what you want, try:
i = 1:5;
j = 0:5;
k = zeros(numel(i),numel(j));
for a = 1:numel(i)
for b = 1:numel(j)
k(a,b) = i(a)^2 + i(a)*j(b) + j(b)^2;
end
end
display(k)
zaxtronix on 13 May 2016
Thanks a lot man, how did you do it using this numel function, I definitely wouldn't have been able to come about it.

Andrei Bobrov on 12 May 2016
Edited: Andrei Bobrov on 12 May 2016
n = 5;
k = tril(((1:n)'*ones(1,n+1)).^2+(1:n)'*(0:n)+(ones(n,1)*(0:n)).^2,1);
with for..end loop
n = 5;
k = zeros(n,n+1);
for ii = 1:5,
jj = 0:ii;
k(ii,1:ii+1) = ii.^2 + ii*jj + jj.^2;
end
zaxtronix on 13 May 2016
thanks, this also works perfectly, except doing an extraction will require one dealing with zeros in the array
Andrei Bobrov on 13 May 2016
hm...
[ii,jj] = ndgrid(1:5,0:5);
k = ii.^2 + ii.*jj + jj.^2;