|
2928
|
1 /* |
|
|
2 |
|
4773
|
3 Copyright (C) 2004 David Bateman |
|
2928
|
4 Copyright (C) 1996, 1997 John W. Eaton |
|
|
5 |
|
|
6 This file is part of Octave. |
|
|
7 |
|
|
8 Octave is free software; you can redistribute it and/or modify it |
|
|
9 under the terms of the GNU General Public License as published by the |
|
7016
|
10 Free Software Foundation; either version 3 of the License, or (at your |
|
|
11 option) any later version. |
|
2928
|
12 |
|
|
13 Octave is distributed in the hope that it will be useful, but WITHOUT |
|
|
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
|
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
|
16 for more details. |
|
|
17 |
|
|
18 You should have received a copy of the GNU General Public License |
|
7016
|
19 along with Octave; see the file COPYING. If not, see |
|
|
20 <http://www.gnu.org/licenses/>. |
|
2928
|
21 |
|
|
22 */ |
|
|
23 |
|
|
24 #ifdef HAVE_CONFIG_H |
|
|
25 #include <config.h> |
|
|
26 #endif |
|
|
27 |
|
|
28 #include "lo-mappers.h" |
|
|
29 |
|
|
30 #include "defun-dld.h" |
|
|
31 #include "error.h" |
|
|
32 #include "gripes.h" |
|
|
33 #include "oct-obj.h" |
|
|
34 #include "utils.h" |
|
|
35 |
|
4773
|
36 #if defined (HAVE_FFTW3) |
|
|
37 #define FFTSRC "@sc{Fftw}" |
|
|
38 #else |
|
|
39 #define FFTSRC "@sc{Fftpack}" |
|
|
40 #endif |
|
2928
|
41 |
|
4773
|
42 static octave_value |
|
|
43 do_fft (const octave_value_list &args, const char *fcn, int type) |
|
2928
|
44 { |
|
4233
|
45 octave_value retval; |
|
2928
|
46 |
|
|
47 int nargin = args.length (); |
|
|
48 |
|
4773
|
49 if (nargin < 1 || nargin > 3) |
|
2928
|
50 { |
|
5823
|
51 print_usage (); |
|
2928
|
52 return retval; |
|
|
53 } |
|
|
54 |
|
|
55 octave_value arg = args(0); |
|
4773
|
56 dim_vector dims = arg.dims (); |
|
5275
|
57 octave_idx_type n_points = -1; |
|
4773
|
58 int dim = -1; |
|
|
59 |
|
|
60 if (nargin > 1) |
|
|
61 { |
|
|
62 if (! args(1).is_empty ()) |
|
|
63 { |
|
|
64 double dval = args(1).double_value (); |
|
|
65 if (xisnan (dval)) |
|
|
66 error ("%s: NaN is invalid as the N_POINTS", fcn); |
|
|
67 else |
|
|
68 { |
|
5275
|
69 n_points = NINTbig (dval); |
|
4773
|
70 if (n_points < 0) |
|
|
71 error ("%s: number of points must be greater than zero", fcn); |
|
|
72 } |
|
|
73 } |
|
|
74 } |
|
2928
|
75 |
|
4773
|
76 if (error_state) |
|
|
77 return retval; |
|
|
78 |
|
|
79 if (nargin > 2) |
|
2928
|
80 { |
|
4773
|
81 double dval = args(2).double_value (); |
|
2928
|
82 if (xisnan (dval)) |
|
4773
|
83 error ("%s: NaN is invalid as the N_POINTS", fcn); |
|
|
84 else if (dval < 1 || dval > dims.length ()) |
|
|
85 error ("%s: invalid dimension along which to perform fft", fcn); |
|
2928
|
86 else |
|
5275
|
87 // to be safe, cast it back to int since dim is an int |
|
4773
|
88 dim = NINT (dval) - 1; |
|
2928
|
89 } |
|
|
90 |
|
|
91 if (error_state) |
|
|
92 return retval; |
|
|
93 |
|
5275
|
94 for (octave_idx_type i = 0; i < dims.length (); i++) |
|
4773
|
95 if (dims(i) < 0) |
|
2928
|
96 return retval; |
|
|
97 |
|
4773
|
98 if (dim < 0) |
|
4869
|
99 { |
|
5275
|
100 for (octave_idx_type i = 0; i < dims.length (); i++) |
|
6620
|
101 if (dims(i) > 1) |
|
4869
|
102 { |
|
|
103 dim = i; |
|
|
104 break; |
|
|
105 } |
|
|
106 |
|
|
107 // And if the first argument is scalar? |
|
|
108 if (dim < 0) |
|
|
109 dim = 1; |
|
|
110 } |
|
2928
|
111 |
|
4773
|
112 if (n_points < 0) |
|
|
113 n_points = dims (dim); |
|
|
114 else |
|
|
115 dims (dim) = n_points; |
|
|
116 |
|
6620
|
117 if (dims.any_zero () || n_points == 0) |
|
|
118 return octave_value (NDArray (dims)); |
|
2928
|
119 |
|
|
120 if (arg.is_real_type ()) |
|
|
121 { |
|
4773
|
122 NDArray nda = arg.array_value (); |
|
2928
|
123 |
|
|
124 if (! error_state) |
|
|
125 { |
|
4773
|
126 nda.resize (dims, 0.0); |
|
|
127 retval = (type != 0 ? nda.ifourier (dim) : nda.fourier (dim)); |
|
2928
|
128 } |
|
|
129 } |
|
|
130 else if (arg.is_complex_type ()) |
|
|
131 { |
|
4773
|
132 ComplexNDArray cnda = arg.complex_array_value (); |
|
2928
|
133 |
|
|
134 if (! error_state) |
|
|
135 { |
|
4773
|
136 cnda.resize (dims, 0.0); |
|
|
137 retval = (type != 0 ? cnda.ifourier (dim) : cnda.fourier (dim)); |
|
2928
|
138 } |
|
|
139 } |
|
|
140 else |
|
|
141 { |
|
4773
|
142 gripe_wrong_type_arg (fcn, arg); |
|
2928
|
143 } |
|
|
144 |
|
|
145 return retval; |
|
|
146 } |
|
|
147 |
|
6620
|
148 /* |
|
|
149 |
|
|
150 %!error(fft()) |
|
|
151 %!assert(fft([]), []) |
|
6621
|
152 %!assert(fft(zeros(10,0)), zeros(10,0)) |
|
|
153 %!assert(fft(zeros(0,10)), zeros(0,10)) |
|
6620
|
154 %!assert(fft(0), 0) |
|
|
155 %!assert(fft(1), 1) |
|
|
156 %!assert(fft(1), 1) |
|
|
157 %!assert(fft(ones(2,2)), [2,2; 0,0]) |
|
|
158 %!assert(fft(eye(2,2)), [1,1; 1,-1]) |
|
|
159 |
|
|
160 */ |
|
|
161 |
|
4773
|
162 |
|
|
163 DEFUN_DLD (fft, args, , |
|
|
164 "-*- texinfo -*-\n\ |
|
|
165 @deftypefn {Loadable Function} {} fft (@var{a}, @var{n}, @var{dim})\n\ |
|
|
166 Compute the FFT of @var{a} using subroutines from\n" |
|
|
167 FFTSRC |
|
|
168 ". The FFT is calculated along the first non-singleton dimension of the\n\ |
|
|
169 array. Thus if @var{a} is a matrix, @code{fft (@var{a})} computes the\n\ |
|
|
170 FFT for each column of @var{a}.\n\ |
|
|
171 \n\ |
|
|
172 If called with two arguments, @var{n} is expected to be an integer\n\ |
|
|
173 specifying the number of elements of @var{a} to use, or an empty\n\ |
|
|
174 matrix to specify that its value should be ignored. If @var{n} is\n\ |
|
|
175 larger than the dimension along which the FFT is calculated, then\n\ |
|
5448
|
176 @var{a} is resized and padded with zeros. Otherwise, if @var{n} is\n\ |
|
4773
|
177 smaller than the dimension along which the FFT is calculated, then\n\ |
|
|
178 @var{a} is truncated.\n\ |
|
|
179 \n\ |
|
5448
|
180 If called with three arguments, @var{dim} is an integer specifying the\n\ |
|
4773
|
181 dimension of the matrix along which the FFT is performed\n\ |
|
6971
|
182 @seealso{ifft, fft2, fftn, fftw}\n\ |
|
5642
|
183 @end deftypefn") |
|
4773
|
184 { |
|
4782
|
185 return do_fft (args, "fft", 0); |
|
4773
|
186 } |
|
|
187 |
|
|
188 |
|
|
189 DEFUN_DLD (ifft, args, , |
|
|
190 "-*- texinfo -*-\n\ |
|
|
191 @deftypefn {Loadable Function} {} ifft (@var{a}, @var{n}, @var{dim})\n\ |
|
|
192 Compute the inverse FFT of @var{a} using subroutines from\n" |
|
|
193 FFTSRC |
|
|
194 ". The inverse FFT is calculated along the first non-singleton dimension\n\ |
|
|
195 of the array. Thus if @var{a} is a matrix, @code{fft (@var{a})} computes\n\ |
|
|
196 the inverse FFT for each column of @var{a}.\n\ |
|
|
197 \n\ |
|
|
198 If called with two arguments, @var{n} is expected to be an integer\n\ |
|
|
199 specifying the number of elements of @var{a} to use, or an empty\n\ |
|
|
200 matrix to specify that its value should be ignored. If @var{n} is\n\ |
|
|
201 larger than the dimension along which the inverse FFT is calculated, then\n\ |
|
|
202 @var{a} is resized and padded with zeros. Otherwise, if@var{n} is\n\ |
|
|
203 smaller than the dimension along which the inverse FFT is calculated,\n\ |
|
|
204 then @var{a} is truncated.\n\ |
|
|
205 \n\ |
|
7001
|
206 If called with three arguments, @var{dim} is an integer specifying the\n\ |
|
4773
|
207 dimension of the matrix along which the inverse FFT is performed\n\ |
|
6971
|
208 @seealso{fft, ifft2, ifftn, fftw}\n\ |
|
5642
|
209 @end deftypefn") |
|
4773
|
210 { |
|
4782
|
211 return do_fft (args, "ifft", 1); |
|
4773
|
212 } |
|
|
213 |
|
2928
|
214 /* |
|
|
215 ;;; Local Variables: *** |
|
|
216 ;;; mode: C++ *** |
|
|
217 ;;; End: *** |
|
|
218 */ |
