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comparison scripts/signal/fftconv.m @ 11085:2beacd515e09

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Update docstrings for convolution family of functions (conv, conv2, fftconv)
author Rik <octave@nomad.inbox5.com>
date Thu, 07 Oct 2010 11:27:03 -0700
parents a1dbe9d80eee
children e79f59d31a74
comparison
equal deleted inserted replaced
11084:0f6c5efce96e 11085:2beacd515e09
16 ## You should have received a copy of the GNU General Public License 16 ## You should have received a copy of the GNU General Public License
17 ## along with Octave; see the file COPYING. If not, see 17 ## along with Octave; see the file COPYING. If not, see
18 ## <http://www.gnu.org/licenses/>. 18 ## <http://www.gnu.org/licenses/>.
19 19
20 ## -*- texinfo -*- 20 ## -*- texinfo -*-
21 ## @deftypefn {Function File} {} fftconv (@var{a}, @var{b}, @var{n}) 21 ## @deftypefn {Function File} {} fftconv (@var{a}, @var{b})
22 ## Return the convolution of the vectors @var{a} and @var{b}, as a vector 22 ## @deftypefnx {Function File} {} fftconv (@var{a}, @var{b}, @var{n})
23 ## with length equal to the @code{length (a) + length (b) - 1}. If @var{a} 23 ## Convolve two vectors using the FFT for computation.
24 ## and @var{b} are the coefficient vectors of two polynomials, the returned 24 ##
25 ## value is the coefficient vector of the product polynomial. 25 ## @code{c = fftconv (@var{a}, @var{b})} returns a vector of length equal to
26 ## @code{length (@var{a}) + length (@var{b}) - 1}.
27 ## If @var{a} and @var{b} are the coefficient vectors of two polynomials, the
28 ## returned value is the coefficient vector of the product polynomial.
26 ## 29 ##
27 ## The computation uses the FFT by calling the function @code{fftfilt}. If 30 ## The computation uses the FFT by calling the function @code{fftfilt}. If
28 ## the optional argument @var{n} is specified, an N-point FFT is used. 31 ## the optional argument @var{n} is specified, an N-point FFT is used.
32 ## @seealso{deconv, conv, conv2}
29 ## @end deftypefn 33 ## @end deftypefn
30 34
31 ## Author: KH <Kurt.Hornik@wu-wien.ac.at> 35 ## Author: KH <Kurt.Hornik@wu-wien.ac.at>
32 ## Created: 3 September 1994 36 ## Created: 3 September 1994
33 ## Adapted-By: jwe 37 ## Adapted-By: jwe
37 if (nargin < 2 || nargin > 3) 41 if (nargin < 2 || nargin > 3)
38 print_usage (); 42 print_usage ();
39 endif 43 endif
40 44
41 if (! (isvector (a) && isvector (b))) 45 if (! (isvector (a) && isvector (b)))
42 error ("fftconv: both a and b should be vectors"); 46 error ("fftconv: both A and B must be vectors");
43 endif 47 endif
44 la = length (a); 48 la = length (a);
45 lb = length (b); 49 lb = length (b);
46 if ((la == 1) || (lb == 1)) 50 if ((la == 1) || (lb == 1))
47 c = a * b; 51 c = a * b;
51 b(lc) = 0; 55 b(lc) = 0;
52 if (nargin == 2) 56 if (nargin == 2)
53 c = fftfilt (a, b); 57 c = fftfilt (a, b);
54 else 58 else
55 if (! (isscalar (N))) 59 if (! (isscalar (N)))
56 error ("fftconv: N has to be a scalar"); 60 error ("fftconv: N must be a scalar");
57 endif 61 endif
58 c = fftfilt (a, b, N); 62 c = fftfilt (a, b, N);
59 endif 63 endif
60 endif 64 endif
61 65
62 endfunction 66 endfunction
67
68 %% FIXME: Borrow tests from conv.m. May need a tolerance on the assert comparison