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1 // f-ifft.cc -*- C++ -*- |
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2 /* |
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3 |
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4 Copyright (C) 1993, 1994, 1995 John W. Eaton |
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5 |
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6 This file is part of Octave. |
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7 |
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8 Octave is free software; you can redistribute it and/or modify it |
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9 under the terms of the GNU General Public License as published by the |
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10 Free Software Foundation; either version 2, or (at your option) any |
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11 later version. |
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12 |
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13 Octave is distributed in the hope that it will be useful, but WITHOUT |
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14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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16 for more details. |
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17 |
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18 You should have received a copy of the GNU General Public License |
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19 along with Octave; see the file COPYING. If not, write to the Free |
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20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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21 |
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22 */ |
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23 |
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240
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24 #ifdef HAVE_CONFIG_H |
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25 #include <config.h> |
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26 #endif |
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27 |
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28 #include "CMatrix.h" |
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29 #include "dMatrix.h" |
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30 |
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31 #include "defun-dld.h" |
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32 #include "error.h" |
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33 #include "gripes.h" |
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34 #include "help.h" |
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35 #include "tree-const.h" |
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36 #include "user-prefs.h" |
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37 #include "utils.h" |
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38 |
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39 // This function should be merged with Ffft. |
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40 |
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41 DEFUN_DLD_BUILTIN ("ifft", Fifft, Sifft, 3, 1, |
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42 "ifft (X [, N]): inverse fast fourier transform of a vector") |
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43 { |
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44 Octave_object retval; |
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45 |
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46 int nargin = args.length (); |
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47 |
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48 if (nargin < 1 || nargin > 2) |
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49 { |
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50 print_usage ("ifft"); |
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51 return retval; |
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52 } |
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53 |
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54 tree_constant arg = args(0); |
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55 |
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56 int n_points = arg.rows (); |
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57 if (n_points == 1) |
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58 n_points = arg.columns (); |
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59 |
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60 if (nargin == 2) |
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61 { |
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62 double dval = args(1).double_value (); |
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63 if (xisnan (dval)) |
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64 error ("fft: NaN is invalid as the N_POINTS"); |
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65 else |
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66 n_points = NINT (dval); |
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67 } |
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68 |
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69 if (error_state) |
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70 return retval; |
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71 |
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72 if (n_points < 0) |
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73 { |
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74 error ("ifft: number of points must be greater than zero"); |
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75 return retval; |
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76 } |
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77 |
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78 int arg_is_empty = empty_arg ("ifft", arg.rows (), arg.columns ()); |
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79 |
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80 if (arg_is_empty < 0) |
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81 return retval; |
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82 else if (arg_is_empty || n_points == 0) |
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83 return Matrix (); |
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84 |
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85 if (arg.is_real_type ()) |
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86 { |
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87 Matrix m = arg.matrix_value (); |
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88 |
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89 if (! error_state) |
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90 { |
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91 if (m.rows () == 1) |
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92 m.resize (1, n_points, 0.0); |
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93 else |
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94 m.resize (n_points, m.columns (), 0.0); |
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95 retval = m.ifourier (); |
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96 } |
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97 } |
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98 else if (arg.is_complex_type ()) |
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99 { |
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100 ComplexMatrix m = arg.complex_matrix_value (); |
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101 |
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102 if (! error_state) |
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103 { |
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104 if (m.rows () == 1) |
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105 m.resize (1, n_points, 0.0); |
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106 else |
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107 m.resize (n_points, m.columns (), 0.0); |
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108 retval = m.ifourier (); |
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109 } |
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110 } |
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111 else |
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112 { |
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113 gripe_wrong_type_arg ("ifft", arg); |
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114 } |
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115 |
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116 return retval; |
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117 } |
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118 |
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119 /* |
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120 ;;; Local Variables: *** |
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121 ;;; mode: C++ *** |
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122 ;;; page-delimiter: "^/\\*" *** |
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123 ;;; End: *** |
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124 */ |
