histogram of angles in a loop

for i=1:n

for j=1:n

angle = transpose(rnorm{i})*rnorm{j};

if angle < cosd(20)

here for every 'i' i want histogram wrt to angles

end

end

end

i need to transform the above code in such a way that for each 'i' histogram(angles) [gap of 0.5 upto 20] has to be stored

rnorm is a 3*1 matrix

urs help is highly appretiated thanks