vectorization

[David Bateman]

David Bateman wrote:
> The final reshape should use size(a) and not size(A).. Thus the code
>
> function q = newfilter1 (A, npoints)
>
>  % assumes A is a muliple of npoints long
>  a = reshape (A, npoints, numel(A) / npoints);
>  q = reshape (repmat (min (abs(A - repmat(mean (A, 1), npoints, 1)), 
> 1),  npoints, 1), size (a));
>
> endfunction
>
> should be used instead. Untested as is the previous code.
>
> D.
>
Sorry take 3.

function q = newfilter (A, npoints)

  % assumes A is a muliple of npoints long
  a = reshape (A, npoints, numel(A) / npoints);
  [dum, idx] = min (abs(a - repmat(mean (a, 1), npoints, 1)), [], 1)
  q = reshape (repmat (a(idx + [0 : numel(A) / npoints - 1] * ...
             npoints), npoints, 1), size (A));

endfunction

Bit hard to test the code at the moment due to lack of a copy of Octave, 
which explains the number of attempts to get it right

D.