Matlab script showing how to use vectoralization to avoid iterations

vectoralization.m

%
% Suppose you have three vector valuated variables, u, v and w:
%
%      +-  -+
%      | u1 |
%  u = | u2 |
%      | u3 |
%      +-  -+
%
%      +-  -+
%      | v1 |
%  v = | v2 |
%      | v3 |
%      +-  -+
%
%      +-  -+
%      | w1 |
%  w = | w2 |
%      | w3 |
%      +-  -+
%
%  and you wanna compute u(j) = 2 * v(j) + 5 * w(j)
%

display(' ')
display('VECTORALIZATION STUDY')
display(' ')


% let's initializa the data vectors

v = [  11;  22;  33 ];
w = [ 100; 200; 300 ];
u_for = zeros(3,1);
u_vec = zeros(3,1);

% -------------------------------------
% you can do that using a for statement

for j = 1:3,
  u_for(j) = 2 * v(j) + 5 * w(j);
end

display('Value of u (throught for)');
display(u_for);

% ---------------------------------------------
% you can achieve that throught vectoralization

u_vec = 2 * v + 5 * w;

display('Value of u (throught vectoralization)');
display(u_vec);

% assert that verifies the result

if u_for == u_vec,
    display('Success');
else
    display('Failure');
end

% graphical user assertion to verify the result

subplot(1,2,1), hist(u_for), title('FOR');
subplot(1,2,2), hist(u_vec), title('VECTORIZED');