Mercurial > hg > octave-lyh
annotate scripts/signal/fftconv.m @ 11540:b0ef6f28e09a
deprecate krylovb function
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Sat, 15 Jan 2011 03:40:32 -0500 |
| parents | fd0a3ac60b0e |
| children | c792872f8942 |
| rev | line source |
|---|---|
| 11523 | 1 ## Copyright (C) 1994-2011 John W. Eaton |
| 2313 | 2 ## |
| 3 ## This file is part of Octave. | |
| 4 ## | |
| 5 ## Octave is free software; you can redistribute it and/or modify it | |
| 6 ## under the terms of the GNU General Public License as published by | |
| 7016 | 7 ## the Free Software Foundation; either version 3 of the License, or (at |
| 8 ## your option) any later version. | |
| 2313 | 9 ## |
| 10 ## Octave is distributed in the hope that it will be useful, but | |
| 11 ## WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 ## General Public License for more details. | |
| 14 ## | |
| 15 ## You should have received a copy of the GNU General Public License | |
| 7016 | 16 ## along with Octave; see the file COPYING. If not, see |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 1026 | 18 |
| 3367 | 19 ## -*- texinfo -*- |
|
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20 ## @deftypefn {Function File} {} fftconv (@var{x}, @var{y}) |
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21 ## @deftypefnx {Function File} {} fftconv (@var{x}, @var{y}, @var{n}) |
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Rik <octave@nomad.inbox5.com>
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22 ## Convolve two vectors using the FFT for computation. |
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23 ## |
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24 ## @code{c = fftconv (@var{x}, @var{y})} returns a vector of length equal to |
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25 ## @code{length (@var{x}) + length (@var{y}) - 1}. |
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26 ## If @var{x} and @var{y} are the coefficient vectors of two polynomials, the |
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27 ## returned value is the coefficient vector of the product polynomial. |
| 3426 | 28 ## |
| 3367 | 29 ## The computation uses the FFT by calling the function @code{fftfilt}. If |
| 30 ## the optional argument @var{n} is specified, an N-point FFT is used. | |
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31 ## @seealso{deconv, conv, conv2} |
| 3367 | 32 ## @end deftypefn |
| 787 | 33 |
| 5428 | 34 ## Author: KH <Kurt.Hornik@wu-wien.ac.at> |
| 2312 | 35 ## Created: 3 September 1994 |
| 36 ## Adapted-By: jwe | |
| 37 | |
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38 function c = fftconv (x, y, n) |
| 787 | 39 |
| 40 if (nargin < 2 || nargin > 3) | |
| 6046 | 41 print_usage (); |
| 787 | 42 endif |
| 2325 | 43 |
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44 if (! (isvector (x) && isvector (y))) |
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parents:
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45 error ("fftconv: both A and B must be vectors"); |
| 787 | 46 endif |
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47 la = length (x); |
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48 lb = length (y); |
| 787 | 49 if ((la == 1) || (lb == 1)) |
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50 c = x * y; |
| 787 | 51 else |
| 52 lc = la + lb - 1; | |
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53 x(lc) = 0; |
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54 y(lc) = 0; |
| 787 | 55 if (nargin == 2) |
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parents:
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56 c = fftfilt (x, y); |
| 787 | 57 else |
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Rik <octave@nomad.inbox5.com>
parents:
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58 if (! isscalar (n)) |
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Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
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59 error ("fftconv: N must be a scalar"); |
| 787 | 60 endif |
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11469
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Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
11124
diff
changeset
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61 c = fftfilt (x, y, n); |
| 787 | 62 endif |
| 63 endif | |
| 64 | |
| 65 endfunction | |
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11085
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
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66 |
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11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
11124
diff
changeset
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67 |
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11085
2beacd515e09
Update docstrings for convolution family of functions (conv, conv2, fftconv)
Rik <octave@nomad.inbox5.com>
parents:
7017
diff
changeset
|
68 %% FIXME: Borrow tests from conv.m. May need a tolerance on the assert comparison |
| 11124 | 69 %!test |
| 70 %! x = ones(3,1); | |
| 71 %! y = ones(1,3); | |
| 72 %! b = 2; | |
| 73 %! c = 3; | |
| 74 %! assert (fftconv (x, x), [1; 2; 3; 2; 1], 5*eps); | |
| 75 %! assert (fftconv (y, y), [1, 2, 3, 2, 1], 5*eps); | |
| 76 %! assert (fftconv (x, y), [1, 2, 3, 2, 1], 5*eps); | |
| 77 %! assert (fftconv (y, x), [1; 2; 3; 2; 1], 5*eps); | |
| 78 %! assert (fftconv (c, x), [3; 3; 3], 5*eps); | |
| 79 %! assert (fftconv (c, y), [3, 3, 3], 5*eps); | |
| 80 %! assert (fftconv (x, c), [3; 3; 3], 5*eps); | |
| 81 %! assert (fftconv (y, c), [3, 3, 3], 5*eps); | |
| 82 %! assert (fftconv (b, c), 6, 5*eps); | |
| 83 | |
| 84 %!test | |
| 85 %! a = 1:10; | |
| 86 %! b = 1:3; | |
| 87 %! assert (size(conv(a,b)), [1, numel(a)+numel(b)-1]) | |
| 88 %! assert (size(conv(b,a)), [1, numel(a)+numel(b)-1]) | |
| 89 | |
| 90 %! a = (1:10).'; | |
| 91 %! b = 1:3; | |
| 92 %! assert (size(conv(a,b)), [numel(a)+numel(b)-1, 1]) | |
| 93 %! assert (size(conv(b,a)), [numel(a)+numel(b)-1, 1]) | |
| 94 | |
| 95 %!test | |
| 96 %! a = 1:10; | |
| 97 %! b = (1:3).'; | |
| 98 %! assert (size(conv(a,b)), [1, numel(a)+numel(b)-1]) | |
| 99 %! assert (size(conv(b,a)), [1, numel(a)+numel(b)-1]) | |
| 100 | |
| 101 %% Test input validation | |
| 102 %!error fftconv (1); | |
| 103 %!error fftconv (1,2,3,4); | |
| 104 %!error fftconv ([1, 2; 3, 4], 3); | |
| 105 %!error fftconv (2, []); | |
| 106 %!error fftconv ([1,1], [2,2] , [3, 4]); |