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1 /* |
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2 |
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3 Copyright (C) 1996, 1997 John W. Eaton |
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4 |
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5 This file is part of Octave. |
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6 |
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7 Octave is free software; you can redistribute it and/or modify it |
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8 under the terms of the GNU General Public License as published by the |
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9 Free Software Foundation; either version 2, or (at your option) any |
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10 later version. |
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11 |
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12 Octave is distributed in the hope that it will be useful, but WITHOUT |
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13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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15 for more details. |
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16 |
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17 You should have received a copy of the GNU General Public License |
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18 along with Octave; see the file COPYING. If not, write to the Free |
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19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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20 |
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21 */ |
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22 |
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23 #ifdef HAVE_CONFIG_H |
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24 #include <config.h> |
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25 #endif |
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26 |
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27 #include "lo-mappers.h" |
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28 |
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29 #include "defun-dld.h" |
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30 #include "error.h" |
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31 #include "gripes.h" |
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32 #include "oct-obj.h" |
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33 #include "utils.h" |
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34 |
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35 // This function should be merged with Fifft. |
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36 |
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37 DEFUN_DLD (fft, args, , |
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38 "-*- texinfo -*-\n\ |
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39 @deftypefn {Loadable Function} {} fft (@var{a}, @var{n})\n\ |
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40 Compute the FFT of @var{a} using subroutines from @sc{Fftpack}. If @var{a}\n\ |
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41 is a matrix, @code{fft} computes the FFT for each column of @var{a}.\n\ |
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42 \n\ |
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43 If called with two arguments, @var{n} is expected to be an integer\n\ |
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44 specifying the number of elements of @var{a} to use. If @var{a} is a\n\ |
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45 matrix, @var{n} specifies the number of rows of @var{a} to use. If\n\ |
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46 @var{n} is larger than the size of @var{a}, @var{a} is resized and\n\ |
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47 padded with zeros.\n\ |
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48 @end deftypefn") |
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49 { |
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4233
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50 octave_value retval; |
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51 |
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52 int nargin = args.length (); |
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53 |
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54 if (nargin < 1 || nargin > 2) |
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55 { |
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56 print_usage ("fft"); |
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57 return retval; |
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58 } |
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59 |
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60 octave_value arg = args(0); |
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61 |
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62 int n_points = arg.rows (); |
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63 if (n_points == 1) |
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64 n_points = arg.columns (); |
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65 |
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66 if (nargin == 2) |
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67 { |
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68 double dval = args(1).double_value (); |
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69 if (xisnan (dval)) |
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70 error ("fft: NaN is invalid as the N_POINTS"); |
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71 else |
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72 n_points = NINT (dval); |
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73 } |
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74 |
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75 if (error_state) |
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76 return retval; |
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77 |
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78 if (n_points < 0) |
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79 { |
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80 error ("fft: number of points must be greater than zero"); |
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81 return retval; |
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82 } |
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83 |
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84 int arg_is_empty = empty_arg ("fft", arg.rows (), arg.columns ()); |
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85 |
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86 if (arg_is_empty < 0) |
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87 return retval; |
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88 else if (arg_is_empty || n_points == 0) |
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89 return octave_value (Matrix ()); |
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90 |
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91 if (arg.is_real_type ()) |
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92 { |
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93 Matrix m = arg.matrix_value (); |
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94 |
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95 if (! error_state) |
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96 { |
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97 if (m.rows () == 1) |
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98 m.resize (1, n_points, 0.0); |
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99 else |
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100 m.resize (n_points, m.columns (), 0.0); |
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101 retval = m.fourier (); |
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102 } |
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103 } |
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104 else if (arg.is_complex_type ()) |
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105 { |
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106 ComplexMatrix m = arg.complex_matrix_value (); |
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107 |
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108 if (! error_state) |
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109 { |
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110 if (m.rows () == 1) |
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111 m.resize (1, n_points, 0.0); |
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112 else |
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113 m.resize (n_points, m.columns (), 0.0); |
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114 retval = m.fourier (); |
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115 } |
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116 } |
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117 else |
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118 { |
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119 gripe_wrong_type_arg ("fft", arg); |
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120 } |
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121 |
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122 return retval; |
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123 } |
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124 |
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125 /* |
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126 ;;; Local Variables: *** |
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127 ;;; mode: C++ *** |
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128 ;;; End: *** |
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129 */ |
