1 | /// \ingroup newmat
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2 | ///@{
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3 |
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4 | /// \file hholder.cpp
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5 | /// QR related decompositions
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6 | /// QRZ, QRZT decompositions
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7 | /// QR update and extend orthogonal functions
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8 |
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9 | // Copyright (C) 1991,2,3,4: R B Davies
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10 |
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11 | #define WANT_MATH
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12 | //#define WANT_STREAM
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13 |
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14 | #include "include.h"
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15 |
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16 | #include "newmatap.h"
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17 |
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18 | #ifdef use_namespace
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19 | namespace NEWMAT {
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20 | #endif
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21 |
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22 | #ifdef DO_REPORT
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23 | #define REPORT { static ExeCounter ExeCount(__LINE__,16); ++ExeCount; }
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24 | #else
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25 | #define REPORT {}
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26 | #endif
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27 |
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28 |
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29 | /*************************** QR decompositions ***************************/
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30 |
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31 | inline Real square(Real x) { return x*x; }
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32 |
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33 | void QRZT(Matrix& X, LowerTriangularMatrix& L)
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34 | {
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35 | REPORT
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36 | Tracer et("QRZT(1)");
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37 | int n = X.Ncols(); int s = X.Nrows(); L.resize(s);
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38 | if (n == 0 || s == 0) { L = 0.0; return; }
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39 | Real* xi = X.Store(); int k;
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40 | for (int i=0; i<s; i++)
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41 | {
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42 | Real sum = 0.0;
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43 | Real* xi0=xi; k=n; while(k--) { sum += square(*xi++); }
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44 | sum = sqrt(sum);
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45 | if (sum == 0.0)
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46 | {
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47 | REPORT
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48 | k=n; while(k--) { *xi0++ = 0.0; }
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49 | for (int j=i; j<s; j++) L.element(j,i) = 0.0;
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50 | }
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51 | else
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52 | {
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53 | L.element(i,i) = sum;
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54 | Real* xj0=xi0; k=n; while(k--) { *xj0++ /= sum; }
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55 | for (int j=i+1; j<s; j++)
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56 | {
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57 | sum=0.0;
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58 | xi=xi0; Real* xj=xj0; k=n; while(k--) { sum += *xi++ * *xj++; }
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59 | xi=xi0; k=n; while(k--) { *xj0++ -= sum * *xi++; }
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60 | L.element(j,i) = sum;
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61 | }
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62 | }
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63 | }
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64 | }
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65 |
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66 | void QRZT(const Matrix& X, Matrix& Y, Matrix& M)
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67 | {
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68 | REPORT
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69 | Tracer et("QRZT(2)");
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70 | int n = X.Ncols(); int s = X.Nrows(); int t = Y.Nrows();
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71 | if (Y.Ncols() != n)
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72 | { Throw(ProgramException("Unequal row lengths",X,Y)); }
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73 | M.resize(t,s);
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74 | Real* xi = X.Store(); int k;
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75 | for (int i=0; i<s; i++)
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76 | {
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77 | Real* xj0 = Y.Store(); Real* xi0 = xi;
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78 | for (int j=0; j<t; j++)
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79 | {
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80 | Real sum=0.0;
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81 | xi=xi0; Real* xj=xj0; k=n; while(k--) { sum += *xi++ * *xj++; }
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82 | xi=xi0; k=n; while(k--) { *xj0++ -= sum * *xi++; }
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83 | M.element(j,i) = sum;
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84 | }
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85 | }
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86 | }
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87 |
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88 | /*
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89 | void QRZ(Matrix& X, UpperTriangularMatrix& U)
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90 | {
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91 | Tracer et("QRZ(1)");
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92 | int n = X.Nrows(); int s = X.Ncols(); U.resize(s);
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93 | Real* xi0 = X.Store(); int k;
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94 | for (int i=0; i<s; i++)
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95 | {
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96 | Real sum = 0.0;
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97 | Real* xi = xi0; k=n; while(k--) { sum += square(*xi); xi+=s; }
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98 | sum = sqrt(sum);
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99 | U.element(i,i) = sum;
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100 | if (sum==0.0) Throw(SingularException(U));
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101 | Real* xj0=xi0; k=n; while(k--) { *xj0 /= sum; xj0+=s; }
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102 | xj0 = xi0;
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103 | for (int j=i+1; j<s; j++)
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104 | {
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105 | sum=0.0;
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106 | xi=xi0; k=n; xj0++; Real* xj=xj0;
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107 | while(k--) { sum += *xi * *xj; xi+=s; xj+=s; }
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108 | xi=xi0; k=n; xj=xj0;
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109 | while(k--) { *xj -= sum * *xi; xj+=s; xi+=s; }
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110 | U.element(i,j) = sum;
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111 | }
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112 | xi0++;
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113 | }
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114 | }
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115 | */
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116 |
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117 | void QRZ(Matrix& X, UpperTriangularMatrix& U)
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118 | {
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119 | REPORT
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120 | Tracer et("QRZ(1)");
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121 | int n = X.Nrows(); int s = X.Ncols(); U.resize(s); U = 0.0;
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122 | if (n == 0 || s == 0) return;
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123 | Real* xi0 = X.Store(); Real* u0 = U.Store(); Real* u;
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124 | int j, k; int J = s; int i = s;
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125 | while (i--)
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126 | {
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127 | Real* xj0 = xi0; Real* xi = xi0; k = n;
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128 | if (k) for (;;)
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129 | {
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130 | u = u0; Real Xi = *xi; Real* xj = xj0;
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131 | j = J; while(j--) *u++ += Xi * *xj++;
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132 | if (!(--k)) break;
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133 | xi += s; xj0 += s;
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134 | }
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135 |
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136 | Real sum = sqrt(*u0); *u0 = sum; u = u0+1;
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137 | if (sum == 0.0)
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138 | {
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139 | REPORT
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140 | j = J - 1; while(j--) *u++ = 0.0;
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141 |
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142 | xj0 = xi0++; k = n;
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143 | if (k) for (;;)
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144 | {
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145 | *xj0 = 0.0;
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146 | if (!(--k)) break;
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147 | xj0 += s;
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148 | }
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149 | u0 += J--;
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150 | }
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151 | else
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152 | {
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153 | int J1 = J-1; j = J1; while(j--) *u++ /= sum;
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154 |
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155 | xj0 = xi0; xi = xi0++; k = n;
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156 | if (k) for (;;)
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157 | {
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158 | u = u0+1; Real Xi = *xi; Real* xj = xj0;
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159 | Xi /= sum; *xj++ = Xi;
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160 | j = J1; while(j--) *xj++ -= *u++ * Xi;
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161 | if (!(--k)) break;
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162 | xi += s; xj0 += s;
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163 | }
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164 | u0 += J--;
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165 | }
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166 | }
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167 | }
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168 |
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169 | void QRZ(const Matrix& X, Matrix& Y, Matrix& M)
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170 | {
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171 | REPORT
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172 | Tracer et("QRZ(2)");
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173 | int n = X.Nrows(); int s = X.Ncols(); int t = Y.Ncols();
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174 | if (Y.Nrows() != n)
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175 | { Throw(ProgramException("Unequal column lengths",X,Y)); }
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176 | M.resize(s,t); M = 0;Real* m0 = M.Store(); Real* m;
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177 | Real* xi0 = X.Store();
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178 | int j, k; int i = s;
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179 | while (i--)
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180 | {
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181 | Real* xj0 = Y.Store(); Real* xi = xi0; k = n;
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182 | if (k) for (;;)
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183 | {
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184 | m = m0; Real Xi = *xi; Real* xj = xj0;
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185 | j = t; while(j--) *m++ += Xi * *xj++;
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186 | if (!(--k)) break;
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187 | xi += s; xj0 += t;
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188 | }
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189 |
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190 | xj0 = Y.Store(); xi = xi0++; k = n;
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191 | if (k) for (;;)
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192 | {
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193 | m = m0; Real Xi = *xi; Real* xj = xj0;
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194 | j = t; while(j--) *xj++ -= *m++ * Xi;
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195 | if (!(--k)) break;
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196 | xi += s; xj0 += t;
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197 | }
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198 | m0 += t;
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199 | }
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200 | }
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201 |
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202 | /*
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203 |
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204 | void QRZ(const Matrix& X, Matrix& Y, Matrix& M)
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205 | {
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206 | Tracer et("QRZ(2)");
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207 | int n = X.Nrows(); int s = X.Ncols(); int t = Y.Ncols();
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208 | if (Y.Nrows() != n)
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209 | { Throw(ProgramException("Unequal column lengths",X,Y)); }
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210 | M.resize(s,t);
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211 | Real* xi0 = X.Store(); int k;
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212 | for (int i=0; i<s; i++)
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213 | {
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214 | Real* xj0 = Y.Store();
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215 | for (int j=0; j<t; j++)
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216 | {
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217 | Real sum=0.0;
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218 | Real* xi=xi0; Real* xj=xj0; k=n;
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219 | while(k--) { sum += *xi * *xj; xi+=s; xj+=t; }
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220 | xi=xi0; k=n; xj=xj0++;
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221 | while(k--) { *xj -= sum * *xi; xj+=t; xi+=s; }
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222 | M.element(i,j) = sum;
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223 | }
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224 | xi0++;
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225 | }
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226 | }
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227 | */
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228 |
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229 | void updateQRZT(Matrix& X, LowerTriangularMatrix& L)
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230 | {
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231 | REPORT
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232 | Tracer et("updateQRZT");
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233 | int n = X.Ncols(); int s = X.Nrows();
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234 | if (s != L.Nrows())
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235 | Throw(ProgramException("Incompatible dimensions",X,L));
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236 | if (n == 0 || s == 0) return;
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237 | Real* xi = X.Store(); int k;
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238 | for (int i=0; i<s; i++)
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239 | {
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240 | Real r = L.element(i,i);
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241 | Real sum = 0.0;
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242 | Real* xi0=xi; k=n; while(k--) { sum += square(*xi++); }
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243 | sum = sqrt(sum + square(r));
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244 | if (sum == 0.0)
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245 | {
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246 | REPORT
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247 | k=n; while(k--) { *xi0++ = 0.0; }
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248 | for (int j=i; j<s; j++) L.element(j,i) = 0.0;
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249 | }
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250 | else
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251 | {
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252 | Real frs = fabs(r) + sum;
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253 | Real a0 = sqrt(frs / sum); Real alpha = a0 / frs;
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254 | if (r <= 0) { REPORT L.element(i,i) = sum; alpha = -alpha; }
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255 | else { REPORT L.element(i,i) = -sum; }
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256 | Real* xj0=xi0; k=n; while(k--) { *xj0++ *= alpha; }
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257 | for (int j=i+1; j<s; j++)
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258 | {
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259 | sum = 0.0;
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260 | xi=xi0; Real* xj=xj0; k=n; while(k--) { sum += *xi++ * *xj++; }
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261 | sum += a0 * L.element(j,i);
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262 | xi=xi0; k=n; while(k--) { *xj0++ -= sum * *xi++; }
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263 | L.element(j,i) -= sum * a0;
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264 | }
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265 | }
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266 | }
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267 | }
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268 |
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269 | void updateQRZ(Matrix& X, UpperTriangularMatrix& U)
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270 | {
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271 | REPORT
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272 | Tracer et("updateQRZ");
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273 | int n = X.Nrows(); int s = X.Ncols();
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274 | if (s != U.Ncols())
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275 | Throw(ProgramException("Incompatible dimensions",X,U));
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276 | if (n == 0 || s == 0) return;
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277 | Real* xi0 = X.Store(); Real* u0 = U.Store(); Real* u;
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278 | RowVector V(s); Real* v0 = V.Store(); Real* v; V = 0.0;
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279 | int j, k; int J = s; int i = s;
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280 | while (i--)
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281 | {
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282 | Real* xj0 = xi0; Real* xi = xi0; k = n;
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283 | if (k) for (;;)
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284 | {
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285 | v = v0; Real Xi = *xi; Real* xj = xj0;
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286 | j = J; while(j--) *v++ += Xi * *xj++;
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287 | if (!(--k)) break;
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288 | xi += s; xj0 += s;
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289 | }
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290 |
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291 | Real r = *u0;
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292 | Real sum = sqrt(*v0 + square(r));
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293 |
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294 | if (sum == 0.0)
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295 | {
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296 | REPORT
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297 | u = u0; v = v0;
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298 | j = J; while(j--) { *u++ = 0.0; *v++ = 0.0; }
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299 | xj0 = xi0++; k = n;
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300 | if (k) for (;;)
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301 | {
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302 | *xj0 = 0.0;
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303 | if (!(--k)) break;
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304 | xj0 += s;
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305 | }
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306 | u0 += J--;
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307 | }
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308 | else
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309 | {
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310 | Real frs = fabs(r) + sum;
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311 | Real a0 = sqrt(frs / sum); Real alpha = a0 / frs;
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312 | if (r <= 0) { REPORT alpha = -alpha; *u0 = sum; }
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313 | else { REPORT *u0 = -sum; }
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314 |
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315 | j = J - 1; v = v0 + 1; u = u0 + 1;
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316 | while (j--)
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317 | { *v = a0 * *u + alpha * *v; *u -= a0 * *v; ++v; ++u; }
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318 |
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319 | xj0 = xi0; xi = xi0++; k = n;
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320 | if (k) for (;;)
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321 | {
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322 | v = v0 + 1; Real Xi = *xi; Real* xj = xj0;
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323 | Xi *= alpha; *xj++ = Xi;
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324 | j = J - 1; while(j--) *xj++ -= *v++ * Xi;
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325 | if (!(--k)) break;
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326 | xi += s; xj0 += s;
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327 | }
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328 |
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329 | j = J; v = v0;
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330 | while (j--) *v++ = 0.0;
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331 |
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332 | u0 += J--;
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333 | }
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334 | }
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335 | }
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336 |
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337 | // Following previous transformation,
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338 | // now apply the same orthogonal transformation to (MX & MU)
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339 | // Need the X Matrix but not the U.
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340 | // Not optimised for accessing consecutive memory
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341 |
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342 | void updateQRZ(const Matrix& X, Matrix& MX, Matrix& MU)
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343 | {
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344 | REPORT
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345 | Tracer et("updateQRZ(2)");
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346 | int s = X.Ncols(); int n = X.Nrows();
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347 | if (n != MX.Nrows())
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348 | Throw(ProgramException("Incompatible dimensions",X,MX));
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349 | if (s != MU.Nrows())
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350 | Throw(ProgramException("Incompatible dimensions",X,MU));
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351 | int t = MX.Ncols();
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352 | if (t != MU.Ncols())
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353 | Throw(ProgramException("Incompatible dimensions",MX,MU));
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354 |
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355 | if (s == 0) return;
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356 |
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357 | const Real* xi0 = X.data(); Real* mx = MX.data(); Real* muj = MU.data();
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358 | for (int i=1; i<=s; ++i)
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359 | {
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360 | Real sum = 0.0;
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361 | {
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362 | const Real* xi=xi0; int k=n;
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363 | while(k--) { sum += square(*xi); xi+= s;}
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364 | }
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365 | Real a0 = sqrt(2.0 - sum); Real* mxj0 = mx;
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366 | for (int j=1; j<=t; ++j)
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367 | {
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368 | Real sum = 0.0;
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369 | const Real* xi=xi0; Real* mxj=mxj0; int k=n;
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370 | while(--k) { sum += *xi * *mxj; xi += s; mxj += t; }
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371 | sum += *xi * *mxj; // last line of loop
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372 | sum += a0 * *muj;
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373 | xi=xi0; mxj=mxj0; k=n;
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374 | while(--k) { *mxj -= sum * *xi; xi += s; mxj += t; }
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375 | *mxj -= sum * *xi; // last line of loop
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376 | *muj -= sum * a0; ++mxj0; ++muj;
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377 | }
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378 | ++xi0;
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379 | }
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380 | }
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381 |
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382 |
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383 |
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384 | // same thing as updateQRZ(Matrix& X, UpperTriangularMatrix& U)
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385 | // except that X is upper triangular
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386 | // contents of X are destroyed - results are in U
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387 | // assume we can access efficiently by columns
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388 | // e.g. X and U will fit in cache memory
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389 |
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390 | void updateQRZ(UpperTriangularMatrix& X, UpperTriangularMatrix& U)
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391 | {
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392 | REPORT
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393 | Tracer et("updateQRZ(3)");
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394 | int s = X.Ncols();
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395 | if (s != U.Ncols())
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396 | Throw(ProgramException("Incompatible dimensions",X,U));
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397 | if (s == 0) return;
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398 | Real* xi0 = X.data(); Real* u = U.data();
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399 | for (int i=1; i<=s; ++i)
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400 | {
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401 | Real r = *u; Real sum = 0.0;
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402 | {
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403 | Real* xi=xi0; int k=i; int l=s;
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404 | while(k--) { sum += square(*xi); xi+= --l;}
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405 | }
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406 | sum = sqrt(sum + square(r));
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407 | if (sum == 0.0) { REPORT X.column(i) = 0.0; *u = 0.0; }
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408 | else
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409 | {
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410 | Real frs = fabs(r) + sum;
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411 | Real a0 = sqrt(frs / sum); Real alpha = a0 / frs;
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412 | if (r <= 0) { REPORT *u = sum; alpha = -alpha; }
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413 | else { REPORT *u = -sum; }
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414 | {
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415 | Real* xj0=xi0; int k=i; int l=s;
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416 | while(k--) { *xj0 *= alpha; --l; xj0 += l;}
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417 | }
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418 | Real* xj0=xi0; Real* uj=u;
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419 | for (int j=i+1; j<=s; ++j)
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420 | {
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421 | Real sum = 0.0; ++xj0; ++uj;
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422 | Real* xi=xi0; Real* xj=xj0; int k=i; int l=s;
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423 | while(k--) { sum += *xi * *xj; --l; xi += l; xj += l; }
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424 | sum += a0 * *uj;
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425 | xi=xi0; xj=xj0; k=i; l=s;
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426 | while(k--) { *xj -= sum * *xi; --l; xi += l; xj += l; }
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427 | *uj -= sum * a0;
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428 | }
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429 | }
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430 | ++xi0; u += s-i+1;
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431 | }
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432 | }
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433 |
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434 | // Following previous transformation,
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435 | // now apply the same orthogonal transformation to (MX & MU)
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436 | // Need the X UpperTriangularMatrix but not the U.
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437 |
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438 | void updateQRZ(const UpperTriangularMatrix& X, Matrix& MX, Matrix& MU)
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439 | {
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440 | REPORT
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441 | Tracer et("updateQRZ(4)");
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442 | int s = X.Ncols();
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443 | if (s != MX.Nrows())
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444 | Throw(ProgramException("Incompatible dimensions",X,MX));
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445 | if (s != MU.Nrows())
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446 | Throw(ProgramException("Incompatible dimensions",X,MU));
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447 | int t = MX.Ncols();
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448 | if (t != MU.Ncols())
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449 | Throw(ProgramException("Incompatible dimensions",MX,MU));
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450 | if (s == 0) return;
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451 |
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452 | const Real* xi0 = X.data(); Real* mx = MX.data(); Real* muj = MU.data();
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453 | for (int i=1; i<=s; ++i)
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454 | {
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455 | Real sum = 0.0;
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456 | {
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457 | const Real* xi=xi0; int k=i; int l=s;
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458 | while(k--) { sum += square(*xi); xi+= --l;}
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459 | }
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460 | Real a0 = sqrt(2.0 - sum); Real* mxj0 = mx;
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461 | for (int j=1; j<=t; ++j)
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462 | {
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463 | Real sum = 0.0;
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464 | const Real* xi=xi0; Real* mxj=mxj0; int k=i; int l=s;
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465 | while(--k) { sum += *xi * *mxj; --l; xi += l; mxj += t; }
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466 | sum += *xi * *mxj; // last line of loop
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467 | sum += a0 * *muj;
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468 | xi=xi0; mxj=mxj0; k=i; l=s;
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469 | while(--k) { *mxj -= sum * *xi; --l; xi += l; mxj += t; }
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470 | *mxj -= sum * *xi; // last line of loop
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471 | *muj -= sum * a0; ++mxj0; ++muj;
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472 | }
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473 | ++xi0;
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474 | }
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475 | }
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476 |
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477 |
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478 |
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479 |
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480 |
|
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481 | // Matrix A's first n columns are orthonormal
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482 | // so A.Columns(1,n).t() * A.Columns(1,n) is the identity matrix.
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483 | // Fill out the remaining columns of A to make them orthonormal
|
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484 | // so A.t() * A is the identity matrix
|
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485 | void extend_orthonormal(Matrix& A, int n)
|
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486 | {
|
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487 | REPORT
|
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488 | Tracer et("extend_orthonormal");
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489 | int nr = A.nrows(); int nc = A.ncols();
|
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490 | if (nc > nr) Throw(IncompatibleDimensionsException(A));
|
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491 | if (n > nc) Throw(IncompatibleDimensionsException(A));
|
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492 | ColumnVector SSR;
|
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493 | { Matrix A1 = A.Columns(1,n); SSR = A1.sum_square_rows(); }
|
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494 | for (int i = n; i < nc; ++i)
|
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495 | {
|
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496 | // pick row with smallest SSQ
|
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497 | int k; SSR.minimum1(k);
|
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498 | // orthogonalise column with 1 at element k, 0 elsewhere
|
---|
499 | // next line is rather inefficient
|
---|
500 | ColumnVector X = - A.Columns(1, i) * A.SubMatrix(k, k, 1, i).t();
|
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501 | X(k) += 1.0;
|
---|
502 | // normalise
|
---|
503 | X /= sqrt(X.SumSquare());
|
---|
504 | // update row sums of squares
|
---|
505 | for (k = 1; k <= nr; ++k) SSR(k) += square(X(k));
|
---|
506 | // load new column into matrix
|
---|
507 | A.Column(i+1) = X;
|
---|
508 | }
|
---|
509 | }
|
---|
510 |
|
---|
511 |
|
---|
512 |
|
---|
513 |
|
---|
514 |
|
---|
515 | #ifdef use_namespace
|
---|
516 | }
|
---|
517 | #endif
|
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518 |
|
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519 |
|
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520 | ///@}
|
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