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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 "CmplxQR.h" |
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28 #include "CmplxQRP.h" |
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29 #include "dbleQR.h" |
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30 #include "dbleQRP.h" |
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31 |
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32 #include "defun-dld.h" |
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33 #include "error.h" |
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34 #include "gripes.h" |
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35 #include "help.h" |
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36 #include "oct-obj.h" |
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37 #include "utils.h" |
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38 |
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39 DEFUN_DLD (qr, args, nargout, |
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40 "[Q, R] = qr (X): form Q unitary and R upper triangular such\n\ |
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41 that Q * R = X\n\ |
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42 \n\ |
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43 [Q, R] = qr (X, 0): form the economy decomposition such that if X is\n\ |
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44 m by n then only the first n columns of Q are\n\ |
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45 computed.\n\ |
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46 \n\ |
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47 [Q, R, P] = qr (X): form QRP factorization of X where\n\ |
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48 P is a permutation matrix such that\n\ |
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49 A * P = Q * R\n\ |
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50 \n\ |
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51 [Q, R, P] = qr (X, 0): form the economy decomposition with \n\ |
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52 permutation vector P such that Q * R = X (:, P)\n\ |
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53 \n\ |
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54 qr (X) alone returns the output of the LAPACK routine dgeqrf, such\n\ |
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55 that R = triu (qr (X))") |
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56 { |
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57 octave_value_list retval; |
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58 |
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59 int nargin = args.length (); |
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60 |
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61 if (nargin != 1 && nargin != 2 || nargout > 3) |
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62 { |
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63 print_usage ("qr"); |
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64 return retval; |
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65 } |
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66 |
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67 octave_value arg = args(0); |
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68 |
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69 int arg_is_empty = empty_arg ("qr", arg.rows (), arg.columns ()); |
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70 |
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71 if (arg_is_empty < 0) |
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72 return retval; |
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73 else if (arg_is_empty > 0) |
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74 return octave_value_list (3, Matrix ()); |
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75 |
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76 QR::type type = nargout == 1 ? QR::raw |
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77 : (nargin == 2 ? QR::economy : QR::std); |
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78 |
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79 if (arg.is_real_type ()) |
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80 { |
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81 Matrix m = arg.matrix_value (); |
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82 |
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83 if (! error_state) |
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84 { |
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85 if (nargout < 3) |
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86 { |
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87 QR fact (m, type); |
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88 retval(1) = fact.R (); |
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89 retval(0) = fact.Q (); |
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90 } |
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91 else |
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92 { |
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93 QRP fact (m, type); |
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94 retval(2) = fact.P (); |
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95 retval(1) = fact.R (); |
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96 retval(0) = fact.Q (); |
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97 } |
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98 } |
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99 } |
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100 else if (arg.is_complex_type ()) |
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101 { |
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102 ComplexMatrix m = arg.complex_matrix_value (); |
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103 |
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104 if (! error_state) |
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105 { |
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106 if (nargout < 3) |
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107 { |
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108 ComplexQR fact (m, type); |
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109 retval(1) = fact.R (); |
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110 retval(0) = fact.Q (); |
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111 } |
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112 else |
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113 { |
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114 ComplexQRP fact (m, type); |
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115 retval(2) = fact.P (); |
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116 retval(1) = fact.R (); |
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117 retval(0) = fact.Q (); |
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118 } |
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119 } |
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120 } |
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121 else |
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122 { |
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123 gripe_wrong_type_arg ("qr", arg); |
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124 } |
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125 |
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126 return retval; |
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127 } |
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128 |
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129 /* |
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130 ;;; Local Variables: *** |
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131 ;;; mode: C++ *** |
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132 ;;; End: *** |
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133 */ |
