1 | #include <itpp/itbase.h> |
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2 | #include <itpp/base/bessel.h> |
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3 | #include "libEF.h" |
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4 | #include <math.h> |
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5 | |
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6 | using namespace itpp; |
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7 | |
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8 | Uniform_RNG UniRNG; |
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9 | Normal_RNG NorRNG; |
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10 | Gamma_RNG GamRNG; |
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11 | |
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12 | using std::cout; |
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13 | |
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14 | vec egiw::sample() const { |
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15 | it_warning("Function not implemented"); |
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16 | return vec_1(0.0); |
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17 | } |
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18 | |
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19 | double egiw::evalpdflog( const vec &val ) const { |
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20 | int nPsi = rv.count()-1; // assuming 1dim y |
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21 | double k = nu + nPsi + 2; |
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22 | |
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23 | double r = val(nPsi); //last entry! |
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24 | vec Psi(nPsi+1); |
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25 | Psi(0) = -1.0; |
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26 | Psi.set_subvector(1,val); // fill the rest |
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27 | |
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28 | return -0.5*( k*log(r) + V.qform(Psi)) - lognc(); |
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29 | } |
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30 | |
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31 | double egiw::lognc() const{ |
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32 | const vec& D = V._D(); |
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33 | int nPsi = D.length()-1; // assuming 1dim y |
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34 | |
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35 | // log(2) = 0.693147180559945286226763983 |
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36 | // log(pi) = 1.144729885849400163877476189 |
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37 | return lgamma(0.5*nu) + 0.5*((1.0-nu)*log(D(0)) - V.logdet() + (nu+nPsi)*0.693147180559945286226763983 + nPsi*1.144729885849400163877476189); |
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38 | } |
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39 | |
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40 | vec egiw::mean() const { |
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41 | const mat &L= V._L(); |
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42 | const vec &D= V._D(); |
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43 | |
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44 | int end = L.rows()-1; |
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45 | vec L0 = L.get_col(0); |
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46 | |
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47 | vec m(D.length()); |
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48 | mat iLsub = ltuinv(L(1,end,1,end)); |
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49 | m.set_subvector(0,iLsub*L0(1,end)); |
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50 | m(end)= D(0)/(nu-2.0); |
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51 | |
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52 | return m; |
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53 | } |
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54 | |
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55 | vec egamma::sample() const { |
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56 | vec smp ( rv.count() ); |
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57 | int i; |
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58 | |
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59 | for ( i=0; i<rv.count(); i++ ) { |
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60 | GamRNG.setup ( alpha ( i ),beta ( i ) ); |
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61 | smp ( i ) = GamRNG(); |
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62 | } |
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63 | |
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64 | return smp; |
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65 | } |
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66 | |
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67 | mat egamma::sample ( int N ) const { |
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68 | mat Smp ( rv.count(),N ); |
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69 | int i,j; |
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70 | |
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71 | for ( i=0; i<rv.count(); i++ ) { |
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72 | GamRNG.setup ( alpha ( i ),beta ( i ) ); |
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73 | |
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74 | for ( j=0; j<N; j++ ) { |
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75 | Smp ( i,j ) = GamRNG(); |
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76 | } |
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77 | } |
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78 | |
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79 | return Smp; |
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80 | } |
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81 | |
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82 | double egamma::evalpdflog ( const vec &val ) const { |
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83 | double res = 0.0; //the rest will be added |
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84 | int i; |
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85 | |
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86 | for ( i=0; i<rv.count(); i++ ) { |
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87 | res += ( alpha ( i ) - 1 ) *std::log ( val ( i ) ) - beta ( i ) *val ( i ); |
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88 | } |
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89 | |
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90 | return res-lognc(); |
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91 | } |
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92 | |
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93 | double egamma::lognc() const { |
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94 | double res = 0.0; //will be added |
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95 | int i; |
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96 | |
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97 | for ( i=0; i<rv.count(); i++ ) { |
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98 | res += lgamma ( alpha ( i ) ) - alpha ( i ) *std::log ( beta ( i ) ) ; |
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99 | } |
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100 | |
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101 | return res; |
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102 | } |
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103 | |
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104 | //MGamma |
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105 | mgamma::mgamma ( const RV &rv,const RV &rvc ) : mEF ( rv,rvc ), epdf ( rv ) {vec* tmp; epdf._param ( tmp,_beta );}; |
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106 | |
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107 | void mgamma::set_parameters ( double k0 ) { |
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108 | k=k0; |
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109 | ep = &epdf; |
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110 | epdf.set_parameters ( k*ones ( rv.count() ),*_beta ); |
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111 | }; |
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112 | |
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113 | vec mgamma::samplecond ( vec &cond, double &ll ) { |
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114 | this->condition(cond ); |
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115 | vec smp = epdf.sample(); |
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116 | ll = epdf.evalpdflog ( smp ); |
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117 | return smp; |
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118 | }; |
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119 | |
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120 | //Fixme repetition of mlnorm.samplecond. |
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121 | mat mgamma::samplecond ( vec &cond, vec &lik, int n ) { |
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122 | int i; |
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123 | int dim = rv.count(); |
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124 | mat Smp ( dim,n ); |
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125 | vec smp ( dim ); |
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126 | this->condition ( cond ); |
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127 | |
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128 | for ( i=0; i<n; i++ ) { |
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129 | smp = epdf.sample(); |
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130 | lik ( i ) = epdf.eval ( smp ); |
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131 | Smp.set_col ( i ,smp ); |
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132 | } |
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133 | |
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134 | return Smp; |
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135 | }; |
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136 | |
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137 | ivec eEmp::resample ( RESAMPLING_METHOD method ) { |
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138 | ivec ind=zeros_i ( n ); |
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139 | ivec N_babies = zeros_i ( n ); |
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140 | vec cumDist = cumsum ( w ); |
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141 | vec u ( n ); |
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142 | int i,j,parent; |
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143 | double u0; |
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144 | |
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145 | switch ( method ) { |
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146 | case MULTINOMIAL: |
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147 | u ( n - 1 ) = pow ( UniRNG.sample(), 1.0 / n ); |
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148 | |
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149 | for ( i = n - 2;i >= 0;i-- ) { |
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150 | u ( i ) = u ( i + 1 ) * pow ( UniRNG.sample(), 1.0 / ( i + 1 ) ); |
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151 | } |
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152 | |
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153 | break; |
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154 | |
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155 | case STRATIFIED: |
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156 | |
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157 | for ( i = 0;i < n;i++ ) { |
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158 | u ( i ) = ( i + UniRNG.sample() ) / n; |
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159 | } |
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160 | |
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161 | break; |
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162 | |
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163 | case SYSTEMATIC: |
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164 | u0 = UniRNG.sample(); |
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165 | |
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166 | for ( i = 0;i < n;i++ ) { |
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167 | u ( i ) = ( i + u0 ) / n; |
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168 | } |
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169 | |
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170 | break; |
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171 | |
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172 | default: |
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173 | it_error ( "PF::resample(): Unknown resampling method" ); |
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174 | } |
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175 | |
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176 | // U is now full |
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177 | j = 0; |
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178 | |
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179 | for ( i = 0;i < n;i++ ) { |
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180 | while ( u ( i ) > cumDist ( j ) ) j++; |
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181 | |
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182 | N_babies ( j ) ++; |
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183 | } |
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184 | |
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185 | // We have assigned new babies for each Particle |
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186 | // Now, we fill the resulting index such that: |
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187 | // * particles with at least one baby should not move * |
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188 | // This assures that reassignment can be done inplace; |
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189 | |
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190 | // find the first parent; |
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191 | parent=0; while ( N_babies ( parent ) ==0 ) parent++; |
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192 | |
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193 | // Build index |
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194 | for ( i = 0;i < n;i++ ) { |
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195 | if ( N_babies ( i ) > 0 ) { |
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196 | ind ( i ) = i; |
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197 | N_babies ( i ) --; //this index was now replicated; |
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198 | } else { |
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199 | // test if the parent has been fully replicated |
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200 | // if yes, find the next one |
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201 | while ( ( N_babies ( parent ) ==0 ) || ( N_babies ( parent ) ==1 && parent>i ) ) parent++; |
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202 | |
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203 | // Replicate parent |
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204 | ind ( i ) = parent; |
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205 | |
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206 | N_babies ( parent ) --; //this index was now replicated; |
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207 | } |
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208 | |
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209 | } |
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210 | |
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211 | // copy the internals according to ind |
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212 | for ( i=0;i<n;i++ ) { |
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213 | if ( ind ( i ) !=i ) { |
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214 | samples ( i ) =samples ( ind ( i ) ); |
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215 | } |
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216 | w ( i ) = 1.0/n; |
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217 | } |
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218 | |
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219 | return ind; |
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220 | } |
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221 | |
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222 | void eEmp::set_parameters ( const vec &w0, epdf* epdf0 ) { |
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223 | //it_assert_debug(rv==epdf0->rv(),"Wrong epdf0"); |
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224 | w=w0; |
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225 | w/=sum ( w0 );//renormalize |
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226 | n=w.length(); |
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227 | samples.set_size ( n ); |
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228 | |
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229 | for ( int i=0;i<n;i++ ) {samples ( i ) =epdf0->sample();} |
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230 | } |
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