(octave.info)Examples

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19.7 Examples
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The following are examples of vectorization questions asked by actual
users of Octave and their solutions.

   • For a vector ‘A’, the following loop

          n = length (A);
          B = zeros (n, 2);
          for i = 1:length (A)
            ## this will be two columns, the first is the difference and
            ## the second the mean of the two elements used for the diff.
            B(i,:) = [A(i+1)-A(i), (A(i+1) + A(i))/2];
          endfor

     can be turned into the following one-liner:

          B = [diff(A)(:), 0.5*(A(1:end-1)+A(2:end))(:)]

     Note the usage of colon indexing to flatten an intermediate result
     into a column vector.  This is a common vectorization trick.