MATLAB: [HELP] Vector loops :'(

matlab for loops vectorize

Anybody knows how can i optimize this? Thanks <3!
 function filter() 
 r=[cos(c) -sin(c);
   sin(c)  cos(c)];
 for i = 1 : n2 
    for j = 1 : n1
        h(i,j) = magic(r(1),std)*magic(r(2),std);
    end
end 
 function y = magic(r,s)
  y = exp(-r^2));

Best Answer

You have set std1 and std2 to equal values. Provided you do that, the result in 'h' is independent of the value 'c' and can be vectorized as:
   n1 = 10;
   n2 = 3;
   s = 2
   h = exp(-(((1-n2)/2:(n2-1)/2)').^2/(2*s^2))*...
       exp(-(((1-n1)/2:(n1-1)/2)).^2/(2*s^2))/s^2/(2*pi);
The code can also be vectorized with unequal values of std1 and std2, but is somewhat more complicated. Do you wish to see that?
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