Storing results from for-loop

Just wondering how I should go about storing all of the values that I get out of this loop in 'idx' without overriding the previous itteration.

idx = []

for i = length (grfcutl)

a = grfcutl{i}

b = find(a<=0)

idx = b(1)

end

Thanks!

Answer 1

[Serhii Tetora]

idx = [];
for i = 1:length(grfcutl)
    a = grfcutl{i};
    idx(end+1) = find(a<=0,1,'first')
end