1 | #include "emix.h" |
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2 | |
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3 | namespace bdm { |
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4 | |
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5 | void emix::set_parameters ( const vec &w0, const Array<epdf*> &Coms0, bool copy ) { |
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6 | w = w0 / sum ( w0 ); |
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7 | dim = Coms0 ( 0 )->dimension(); |
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8 | bool isnamed = Coms0 ( 0 )->isnamed(); |
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9 | int i; |
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10 | RV tmp_rv; |
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11 | if ( isnamed ) tmp_rv = Coms0 ( 0 )->_rv(); |
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12 | |
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13 | for ( i = 0; i < w.length(); i++ ) { |
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14 | it_assert_debug ( dim == ( Coms0 ( i )->dimension() ), "Component sizes do not match!" ); |
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15 | it_assert_debug ( !isnamed || tmp_rv.equal ( Coms0 ( i )->_rv() ), "Component RVs do not match!" ); |
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16 | } |
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17 | if ( copy ) { |
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18 | Coms.set_length ( Coms0.length() ); |
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19 | for ( i = 0; i < w.length(); i++ ) { |
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20 | it_error ( "Not imp..." ); |
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21 | *Coms ( i ) = *Coms0 ( i ); |
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22 | } |
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23 | destroyComs = true; |
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24 | } else { |
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25 | Coms = Coms0; |
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26 | destroyComs = false; |
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27 | } |
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28 | if ( isnamed ) epdf::set_rv ( tmp_rv ); //coms aer already OK, no need for set_rv |
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29 | } |
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30 | |
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31 | vec emix::sample() const { |
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32 | //Sample which component |
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33 | vec cumDist = cumsum ( w ); |
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34 | double u0; |
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35 | #pragma omp critical |
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36 | u0 = UniRNG.sample(); |
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37 | |
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38 | int i = 0; |
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39 | while ( ( cumDist ( i ) < u0 ) && ( i < ( w.length() - 1 ) ) ) { |
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40 | i++; |
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41 | } |
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42 | |
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43 | return Coms ( i )->sample(); |
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44 | } |
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45 | |
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46 | emix* emix::marginal ( const RV &rv ) const { |
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47 | it_assert_debug ( isnamed(), "rvs are not assigned" ); |
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48 | |
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49 | Array<epdf*> Cn ( Coms.length() ); |
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50 | for ( int i = 0; i < Coms.length(); i++ ) { |
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51 | Cn ( i ) = Coms ( i )->marginal ( rv ); |
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52 | } |
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53 | emix* tmp = new emix(); |
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54 | tmp->set_parameters ( w, Cn, false ); |
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55 | tmp->ownComs(); |
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56 | return tmp; |
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57 | } |
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58 | |
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59 | mratio* emix::condition ( const RV &rv ) const { |
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60 | it_assert_debug ( isnamed(), "rvs are not assigned" ); |
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61 | return new mratio ( this, rv ); |
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62 | }; |
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63 | |
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64 | void egiwmix::set_parameters ( const vec &w0, const Array<egiw*> &Coms0, bool copy ) { |
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65 | w = w0 / sum ( w0 ); |
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66 | dim = Coms0 ( 0 )->dimension(); |
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67 | int i; |
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68 | for ( i = 0; i < w.length(); i++ ) { |
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69 | it_assert_debug ( dim == ( Coms0 ( i )->dimension() ), "Component sizes do not match!" ); |
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70 | } |
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71 | if ( copy ) { |
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72 | Coms.set_length ( Coms0.length() ); |
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73 | for ( i = 0; i < w.length(); i++ ) { |
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74 | it_error ( "Not imp..." ); |
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75 | *Coms ( i ) = *Coms0 ( i ); |
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76 | } |
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77 | destroyComs = true; |
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78 | } else { |
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79 | Coms = Coms0; |
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80 | destroyComs = false; |
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81 | } |
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82 | } |
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83 | |
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84 | vec egiwmix::sample() const { |
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85 | //Sample which component |
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86 | vec cumDist = cumsum ( w ); |
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87 | double u0; |
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88 | #pragma omp critical |
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89 | u0 = UniRNG.sample(); |
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90 | |
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91 | int i = 0; |
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92 | while ( ( cumDist ( i ) < u0 ) && ( i < ( w.length() - 1 ) ) ) { |
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93 | i++; |
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94 | } |
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95 | |
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96 | return Coms ( i )->sample(); |
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97 | } |
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98 | |
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99 | vec egiwmix::mean() const { |
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100 | int i; |
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101 | vec mu = zeros ( dim ); |
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102 | for ( i = 0; i < w.length(); i++ ) { |
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103 | mu += w ( i ) * Coms ( i )->mean(); |
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104 | } |
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105 | return mu; |
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106 | } |
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107 | |
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108 | vec egiwmix::variance() const { |
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109 | // non-central moment |
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110 | vec mom2 = zeros ( dim ); |
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111 | for ( int i = 0; i < w.length(); i++ ) { |
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112 | // pow is overloaded, we have to use another approach |
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113 | mom2 += w ( i ) * ( Coms ( i )->variance() + elem_mult ( Coms ( i )->mean(), Coms ( i )->mean() ) ); |
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114 | } |
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115 | // central moment |
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116 | // pow is overloaded, we have to use another approach |
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117 | return mom2 - elem_mult ( mean(), mean() ); |
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118 | } |
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119 | |
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120 | emix* egiwmix::marginal ( const RV &rv ) const { |
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121 | it_assert_debug ( isnamed(), "rvs are not assigned" ); |
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122 | |
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123 | Array<epdf*> Cn ( Coms.length() ); |
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124 | for ( int i = 0; i < Coms.length(); i++ ) { |
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125 | Cn ( i ) = Coms ( i )->marginal ( rv ); |
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126 | } |
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127 | emix* tmp = new emix(); |
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128 | tmp->set_parameters ( w, Cn, false ); |
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129 | tmp->ownComs(); |
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130 | return tmp; |
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131 | } |
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132 | |
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133 | egiw* egiwmix::approx() { |
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134 | // NB: dimx == 1 !!! |
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135 | // The following code might look a bit spaghetti-like, |
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136 | // consult Dedecius, K. et al.: Partial forgetting in AR models. |
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137 | |
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138 | double sumVecCommon; // common part for many terms in eq. |
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139 | int len = w.length(); // no. of mix components |
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140 | int dimLS = Coms ( 1 )->_V()._D().length() - 1; // dim of LS |
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141 | vec vecNu ( len ); // vector of dfms of components |
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142 | vec vecD ( len ); // vector of LS reminders of comps. |
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143 | vec vecCommon ( len ); // vector of common parts |
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144 | mat matVecsTheta; // matrix which rows are theta vects. |
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145 | |
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146 | // fill in the vectors vecNu, vecD and matVecsTheta |
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147 | for ( int i = 0; i < len; i++ ) { |
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148 | vecNu.shift_left ( Coms ( i )->_nu() ); |
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149 | vecD.shift_left ( Coms ( i )->_V()._D() ( 0 ) ); |
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150 | matVecsTheta.append_row ( Coms ( i )->est_theta() ); |
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151 | } |
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152 | |
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153 | // calculate the common parts and their sum |
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154 | vecCommon = elem_mult ( w, elem_div ( vecNu, vecD ) ); |
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155 | sumVecCommon = sum ( vecCommon ); |
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156 | |
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157 | // LS estimator of theta |
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158 | vec aprEstTheta ( dimLS ); |
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159 | aprEstTheta.zeros(); |
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160 | for ( int i = 0; i < len; i++ ) { |
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161 | aprEstTheta += matVecsTheta.get_row ( i ) * vecCommon ( i ); |
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162 | } |
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163 | aprEstTheta /= sumVecCommon; |
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164 | |
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165 | |
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166 | // LS estimator of dfm |
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167 | double aprNu; |
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168 | double A = log ( sumVecCommon ); // Term 'A' in equation |
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169 | |
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170 | for ( int i = 0; i < len; i++ ) { |
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171 | A += w ( i ) * ( log ( vecD ( i ) ) - psi ( 0.5 * vecNu ( i ) ) ); |
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172 | } |
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173 | |
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174 | aprNu = ( 1 + sqrt ( 1 + 2 * ( A - LOG2 ) / 3 ) ) / ( 2 * ( A - LOG2 ) ); |
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175 | |
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176 | |
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177 | // LS reminder (term D(0,0) in C-syntax) |
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178 | double aprD = aprNu / sumVecCommon; |
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179 | |
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180 | // Aproximation of cov |
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181 | // the following code is very numerically sensitive, thus |
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182 | // we have to eliminate decompositions etc. as much as possible |
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183 | mat aprC = zeros ( dimLS, dimLS ); |
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184 | for ( int i = 0; i < len; i++ ) { |
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185 | aprC += Coms ( i )->est_theta_cov().to_mat() * w ( i ); |
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186 | vec tmp = ( matVecsTheta.get_row ( i ) - aprEstTheta ); |
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187 | aprC += vecCommon ( i ) * outer_product ( tmp, tmp ); |
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188 | } |
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189 | |
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190 | // Construct GiW pdf :: BEGIN |
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191 | ldmat aprCinv ( inv ( aprC ) ); |
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192 | vec D = concat ( aprD, aprCinv._D() ); |
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193 | mat L = eye ( dimLS + 1 ); |
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194 | L.set_submatrix ( 1, 0, aprCinv._L() * aprEstTheta ); |
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195 | L.set_submatrix ( 1, 1, aprCinv._L() ); |
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196 | ldmat aprLD ( L, D ); |
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197 | |
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198 | egiw* aprgiw = new egiw ( 1, aprLD, aprNu ); |
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199 | return aprgiw; |
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200 | }; |
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201 | |
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202 | vec mmix::samplecond(const vec &cond) { |
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203 | //Sample which component |
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204 | vec cumDist = cumsum ( w ); |
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205 | double u0; |
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206 | #pragma omp critical |
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207 | u0 = UniRNG.sample(); |
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208 | |
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209 | int i = 0; |
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210 | while ( ( cumDist ( i ) < u0 ) && ( i < ( w.length() - 1 ) ) ) { |
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211 | i++; |
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212 | } |
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213 | |
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214 | return Coms ( i )->samplecond(cond); |
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215 | } |
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216 | |
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217 | } |
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218 | // mprod::mprod ( Array<mpdf*> mFacs, bool overlap) : mpdf ( RV(), RV() ), n ( mFacs.length() ), epdfs ( n ), mpdfs ( mFacs ), rvinds ( n ), rvcinrv ( n ), irvcs_rvc ( n ) { |
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219 | // int i; |
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220 | // bool rvaddok; |
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221 | // // Create rv |
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222 | // for ( i = 0;i < n;i++ ) { |
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223 | // rvaddok=rv.add ( mpdfs ( i )->_rv() ); //add rv to common rvs. |
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224 | // // If rvaddok==false, mpdfs overlap => assert error. |
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225 | // it_assert_debug(rvaddok||overlap,"mprod::mprod() input mpdfs overlap in rv!"); |
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226 | // epdfs ( i ) = & ( mpdfs ( i )->posterior() ); // add pointer to epdf |
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227 | // }; |
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228 | // // Create rvc |
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229 | // for ( i = 0;i < n;i++ ) { |
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230 | // rvc.add ( mpdfs ( i )->_rvc().subt ( rv ) ); //add rv to common rvs. |
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231 | // }; |
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232 | // |
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233 | // // independent = true; |
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234 | // //test rvc of mpdfs and fill rvinds |
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235 | // for ( i = 0;i < n;i++ ) { |
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236 | // // find ith rv in common rv |
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237 | // rvsinrv ( i ) = mpdfs ( i )->_rv().dataind ( rv ); |
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238 | // // find ith rvc in common rv |
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239 | // rvcinrv ( i ) = mpdfs ( i )->_rvc().dataind ( rv ); |
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240 | // // find ith rvc in common rv |
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241 | // irvcs_rvc ( i ) = mpdfs ( i )->_rvc().dataind ( rvc ); |
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242 | // // |
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243 | // /* if ( rvcinrv ( i ).length() >0 ) {independent = false;} |
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244 | // if ( irvcs_rvc ( i ).length() >0 ) {independent = false;}*/ |
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245 | // } |
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246 | // }; |
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