Mercurial > hg > octave-terminal
changeset 13092:186c3b80ba54
codesprint: Tests for fftfilt()
* fftfilt.m: Add tests. Adjust coding style to more modern Octave conventions.
Add more input validation.
author | Rik <octave@nomad.inbox5.com> |
---|---|
date | Sat, 03 Sep 2011 16:26:20 -0700 |
parents | e5aaba072d2b |
children | 1a21c4c5eeeb |
files | scripts/signal/fftfilt.m |
diffstat | 1 files changed, 55 insertions(+), 12 deletions(-) [+] |
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line diff
--- a/scripts/signal/fftfilt.m +++ b/scripts/signal/fftfilt.m @@ -54,8 +54,12 @@ [r_x, c_x] = size (x); [r_b, c_b] = size (b); - if min ([r_b, c_b]) != 1 - error ("fftfilt: B should be a vector"); + if (! isvector (b)) + error ("fftfilt: B must be a vector"); + endif + + if (ndims (x) != 2) + error ("fftfilt: X must be a 1-D or 2-D array"); endif l_b = r_b * c_b; @@ -64,18 +68,18 @@ if (nargin == 2) ## Use FFT with the smallest power of 2 which is >= length (x) + ## length (b) - 1 as number of points ... - n = 2 ^ (ceil (log (r_x + l_b - 1) / log (2))); + n = 2 ^ nextpow2 (r_x + l_b - 1); B = fft (b, n); - y = ifft (fft (x, n) .* B(:,ones (1, c_x))); + y = ifft (fft (x, n) .* B(:, ones (1, c_x))); else ## Use overlap-add method ... if (! (isscalar (n))) error ("fftfilt: N has to be a scalar"); endif - n = 2 ^ (ceil (log (max ([n, l_b])) / log (2))); + n = 2 ^ nextpow2 (max ([n, l_b])); L = n - l_b + 1; B = fft (b, n); - B = B(:,ones (c_x,1)); + B = B(:, ones (c_x,1)); R = ceil (r_x / L); y = zeros (r_x, c_x); for r = 1:R; @@ -89,20 +93,59 @@ endfor endif - y = y(1:r_x,:); + y = y(1:r_x, :); if (transpose) y = y.'; endif - ## Final cleanups: if both x and b are real respectively integer, y - ## should also be + ## Final cleanups: If both x and b are real, y should be real. + ## If both x and b are integer, y should be integer. if (isreal (b) && isreal (x)) y = real (y); endif - if (! any (b - round (b))) - idx = !any (x - round (x)); - y(:,idx) = round (y(:,idx)); + if (! any (b - fix (b))) + idx = !any (x - fix (x)); + y(:, idx) = round (y(:, idx)); endif endfunction + + +%!shared b, x, r +%!test +%! b = [1 1]; +%! x = [1, zeros(1,9)]; +%! assert(fftfilt(b, x ), [1 1 0 0 0 0 0 0 0 0] , eps); +%! assert(fftfilt(b, x.'), [1 1 0 0 0 0 0 0 0 0].', eps); +%! assert(fftfilt(b.',x ), [1 1 0 0 0 0 0 0 0 0] , eps); +%! assert(fftfilt(b.',x.'), [1 1 0 0 0 0 0 0 0 0].', eps); + +%!test +%! r = sqrt(1/2) * (1+i); +%! b = b*r; +%! assert(fftfilt(b, x ), r*[1 1 0 0 0 0 0 0 0 0] , eps); +%! assert(fftfilt(b, r*x), r*r*[1 1 0 0 0 0 0 0 0 0], eps); +%! assert(fftfilt(b, x.'), r*[1 1 0 0 0 0 0 0 0 0].', eps); + +%!test +%! b = [1 1]; +%! x = zeros (10,3); x(1,1)=-1; x(1,2)=1; +%! y0 = zeros (10,3); y0(1:2,1)=-1; y0(1:2,2)=1; +%! y = fftfilt (b, x); +%! assert (y,y0); + +%!test +%! b = rand (10, 1); +%! x = rand (10, 1); +%! y0 = filter (b, 1, x); +%! y = filter (b, 1, x); +%! assert (y, y0); + +%% Test input validation +%!error fftfilt (1) +%!error fftfilt (1, 2, 3, 4) +%!error fftfilt (ones (2), 1) +%!error fftfilt (2, ones (3,3,3)) +%!error fftfilt (2, 1, ones (2)) +