5 | | namespace bdm |
6 | | { |
7 | | |
8 | | merger_base::merger_base(const Array<mpdf*> &S, bool own) { |
9 | | DBG = false; |
10 | | dbg_file = NULL; |
11 | | set_sources(S, own); |
12 | | } |
13 | | |
14 | | vec merger_base::merge_points ( mat &lW ) { |
15 | | int nu=lW.rows(); |
16 | | vec result; |
17 | | ivec indW; |
18 | | bool infexist; |
19 | | switch ( METHOD ) { |
20 | | case ARITHMETIC: |
21 | | result= log ( sum ( exp ( lW ) ) ); //ugly! |
22 | | break; |
23 | | case GEOMETRIC: |
24 | | result= sum ( lW ) /nu; |
25 | | break; |
26 | | case LOGNORMAL: |
27 | | vec sumlW=sum ( lW ) ; |
28 | | indW=find((sumlW<inf) & (sumlW>-inf)); |
29 | | infexist=(indW.size()<lW.cols()); |
30 | | vec mu; |
31 | | vec lam; |
32 | | if (infexist){ |
33 | | mu = sumlW(indW) /nu; //mean of logs |
34 | | // |
35 | | mat validlW=lW.get_cols(indW); |
36 | | lam = sum ( pow ( validlW-outer_product ( ones ( validlW.rows() ),mu ),2 ) ); |
37 | | } |
38 | | else { |
39 | | mu = sum ( lW ) /nu; //mean of logs |
40 | | lam = sum ( pow ( lW-outer_product ( ones ( lW.rows() ),mu ),2 ) ); |
41 | | } |
42 | | // |
43 | | double coef=0.0; |
44 | | vec sq2bl=sqrt ( 2*beta*lam ); //this term is everywhere |
45 | | switch ( nu ) { |
46 | | case 2: |
47 | | coef= ( 1-0.5*sqrt ( ( 4.0*beta-3.0 ) /beta ) ); |
48 | | result =coef*sq2bl + mu ; |
49 | | break; |
50 | | // case 4: == can be done similar to case 2 - is it worth it??? |
51 | | default: // see accompanying document merge_lognorm_derivation.lyx |
52 | | coef = sqrt(1-(nu+1)/(2*beta*nu)); |
53 | | result =log(besselk((nu-3)/2, sq2bl*coef))-log(besselk((nu-3)/2, sq2bl)) + mu; |
54 | | break; |
55 | | } |
56 | | break; |
57 | | } |
58 | | if (infexist){ |
59 | | vec tmp =-inf*ones(lW.cols()); |
60 | | set_subvector(tmp, indW, result); |
61 | | return tmp; |
62 | | } |
63 | | else {return result;} |
64 | | } |
65 | | |
66 | | void merger_mix::merge ( ) |
67 | | { |
68 | | Array<vec> &Smp = eSmp._samples(); //aux |
69 | | vec &w = eSmp._w(); //aux |
70 | | |
71 | | mat Smp_ex =ones ( dim +1,Npoints ); // Extended samples for the ARX model - the last row is ones |
72 | | for ( int i=0;i<Npoints;i++ ) { set_col_part ( Smp_ex,i,Smp ( i ) );} |
73 | | |
74 | | if ( DBG ) *dbg_file << Name ( "Smp_0" ) << Smp_ex; |
75 | | |
76 | | // Stuff for merging |
77 | | vec lw_src ( Npoints ); // weights of the ith source |
78 | | vec lw_mix ( Npoints ); // weights of the approximating mixture |
79 | | vec lw ( Npoints ); // tmp |
80 | | mat lW=zeros ( Nsources,Npoints ); // array of weights of all sources |
81 | | vec vec0 ( 0 ); |
82 | | |
83 | | //initialize importance weights |
84 | | lw_mix = 1.0; // assuming uniform grid density -- otherwise |
85 | | |
86 | | // Initial component in the mixture model |
87 | | mat V0=1e-8*eye ( dim +1 ); |
88 | | ARX A0; A0.set_statistics ( dim, V0 ); //initial guess of Mix: |
89 | | |
90 | | Mix.init ( &A0, Smp_ex, Ncoms ); |
91 | | //Preserve initial mixture for repetitive estimation via flattening |
92 | | MixEF Mix_init ( Mix ); |
93 | | |
94 | | // ============= MAIN LOOP ================== |
95 | | bool converged=false; |
96 | | int niter = 0; |
97 | | char dbg_str[100]; |
98 | | |
99 | | emix* Mpred=Mix.epredictor ( ); |
100 | | vec Mix_pdf ( Npoints ); |
101 | | while ( !converged ) |
102 | | { |
103 | | //Re-estimate Mix |
104 | | //Re-Initialize Mixture model |
105 | | Mix.flatten ( &Mix_init ); |
106 | | Mix.bayesB ( Smp_ex, w*Npoints ); |
107 | | delete Mpred; |
108 | | Mpred = Mix.epredictor ( ); // Allocation => must be deleted at the end!! |
109 | | Mpred->set_rv ( rv ); //the predictor predicts rv of this merger |
110 | | |
111 | | // This will be active only later in iterations!!! |
112 | | if ( 1./sum_sqr ( w ) <effss_coef*Npoints ) |
113 | | { |
114 | | // Generate new samples |
115 | | eSmp.set_samples ( Mpred ); |
116 | | for ( int i=0;i<Npoints;i++ ) |
117 | | { |
118 | | //////////// !!!!!!!!!!!!! |
119 | | //if ( Smp ( i ) ( 2 ) <0 ) {Smp ( i ) ( 2 ) = 0.01; } |
120 | | set_col_part ( Smp_ex,i,Smp ( i ) ); |
121 | | //Importance of the mixture |
122 | | //lw_mix ( i ) =Mix.logpred (Smp_ex.get_col(i) ); |
123 | | lw_mix ( i ) = Mpred->evallog ( Smp ( i ) ); |
124 | | } |
125 | | if ( DBG ) |
126 | | { |
127 | | cout<<"Resampling =" << 1./sum_sqr ( w ) << endl; |
128 | | cout << Mix._e()->mean() <<endl; |
129 | | cout << sum ( Smp_ex,2 ) /Npoints <<endl; |
130 | | cout << Smp_ex*Smp_ex.T() /Npoints << endl; |
131 | | } |
132 | | } |
133 | | if ( DBG ) |
134 | | { |
135 | | sprintf ( dbg_str,"Mpred_mean%d",niter ); |
136 | | *dbg_file << Name ( dbg_str ) << Mpred->mean(); |
137 | | sprintf ( dbg_str,"Mpred_var%d",niter ); |
138 | | *dbg_file << Name ( dbg_str ) << Mpred->variance(); |
139 | | |
140 | | |
141 | | sprintf ( dbg_str,"Mpdf%d",niter ); |
142 | | for ( int i=0;i<Npoints;i++ ) {Mix_pdf ( i ) = Mix.logpred ( Smp_ex.get_col ( i ) );} |
143 | | *dbg_file << Name ( dbg_str ) << Mix_pdf; |
144 | | |
145 | | sprintf ( dbg_str,"Smp%d",niter ); |
146 | | *dbg_file << Name ( dbg_str ) << Smp_ex; |
147 | | |
148 | | } |
149 | | //Importace weighting |
150 | | for ( int i=0;i<mpdfs.length();i++ ) |
151 | | { |
152 | | lw_src=0.0; |
153 | | //======== Same RVs =========== |
154 | | //Split according to dependency in rvs |
155 | | if ( mpdfs ( i )->dimension() ==dim ) |
156 | | { |
157 | | // no need for conditioning or marginalization |
158 | | lw_src = mpdfs ( i )->e()->evallog_m ( Smp ); |
159 | | } |
160 | | else |
161 | | { |
162 | | // compute likelihood of marginal on the conditional variable |
163 | | if ( mpdfs ( i )->dimensionc() >0 ) |
164 | | { |
165 | | // Make marginal on rvc_i |
166 | | epdf* tmp_marg = Mpred->marginal ( mpdfs ( i )->_rvc() ); |
167 | | //compute vector of lw_src |
168 | | for ( int k=0;k<Npoints;k++ ) |
169 | | { |
170 | | // Here val of tmp_marg = cond of mpdfs(i) ==> calling dls->get_cond |
171 | | lw_src ( k ) += tmp_marg->evallog ( dls ( i )->get_cond ( Smp ( k ) ) ); |
172 | | } |
173 | | delete tmp_marg; |
| 5 | namespace bdm { |
| 6 | |
| 7 | merger_base::merger_base ( const Array<mpdf*> &S, bool own ) { |
| 8 | DBG = false; |
| 9 | dbg_file = NULL; |
| 10 | set_sources ( S, own ); |
| 11 | } |
| 12 | |
| 13 | vec merger_base::merge_points ( mat &lW ) { |
| 14 | int nu = lW.rows(); |
| 15 | vec result; |
| 16 | ivec indW; |
| 17 | bool infexist; |
| 18 | switch ( METHOD ) { |
| 19 | case ARITHMETIC: |
| 20 | result = log ( sum ( exp ( lW ) ) ); //ugly! |
| 21 | break; |
| 22 | case GEOMETRIC: |
| 23 | result = sum ( lW ) / nu; |
| 24 | break; |
| 25 | case LOGNORMAL: |
| 26 | vec sumlW = sum ( lW ) ; |
| 27 | indW = find ( ( sumlW < inf ) & ( sumlW > -inf ) ); |
| 28 | infexist = ( indW.size() < lW.cols() ); |
| 29 | vec mu; |
| 30 | vec lam; |
| 31 | if ( infexist ) { |
| 32 | mu = sumlW ( indW ) / nu; //mean of logs |
| 33 | // |
| 34 | mat validlW = lW.get_cols ( indW ); |
| 35 | lam = sum ( pow ( validlW - outer_product ( ones ( validlW.rows() ), mu ), 2 ) ); |
| 36 | } else { |
| 37 | mu = sum ( lW ) / nu; //mean of logs |
| 38 | lam = sum ( pow ( lW - outer_product ( ones ( lW.rows() ), mu ), 2 ) ); |
| 39 | } |
| 40 | // |
| 41 | double coef = 0.0; |
| 42 | vec sq2bl = sqrt ( 2 * beta * lam ); //this term is everywhere |
| 43 | switch ( nu ) { |
| 44 | case 2: |
| 45 | coef = ( 1 - 0.5 * sqrt ( ( 4.0 * beta - 3.0 ) / beta ) ); |
| 46 | result = coef * sq2bl + mu ; |
| 47 | break; |
| 48 | // case 4: == can be done similar to case 2 - is it worth it??? |
| 49 | default: // see accompanying document merge_lognorm_derivation.lyx |
| 50 | coef = sqrt ( 1 - ( nu + 1 ) / ( 2 * beta * nu ) ); |
| 51 | result = log ( besselk ( ( nu - 3 ) / 2, sq2bl * coef ) ) - log ( besselk ( ( nu - 3 ) / 2, sq2bl ) ) + mu; |
| 52 | break; |
| 53 | } |
| 54 | break; |
| 55 | } |
| 56 | if ( infexist ) { |
| 57 | vec tmp = -inf * ones ( lW.cols() ); |
| 58 | set_subvector ( tmp, indW, result ); |
| 59 | return tmp; |
| 60 | } else { |
| 61 | return result; |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | void merger_mix::merge ( ) { |
| 66 | Array<vec> &Smp = eSmp._samples(); //aux |
| 67 | vec &w = eSmp._w(); //aux |
| 68 | |
| 69 | mat Smp_ex = ones ( dim + 1, Npoints ); // Extended samples for the ARX model - the last row is ones |
| 70 | for ( int i = 0; i < Npoints; i++ ) { |
| 71 | set_col_part ( Smp_ex, i, Smp ( i ) ); |
| 72 | } |
| 73 | |
| 74 | if ( DBG ) *dbg_file << Name ( "Smp_0" ) << Smp_ex; |
| 75 | |
| 76 | // Stuff for merging |
| 77 | vec lw_src ( Npoints ); // weights of the ith source |
| 78 | vec lw_mix ( Npoints ); // weights of the approximating mixture |
| 79 | vec lw ( Npoints ); // tmp |
| 80 | mat lW = zeros ( Nsources, Npoints ); // array of weights of all sources |
| 81 | vec vec0 ( 0 ); |
| 82 | |
| 83 | //initialize importance weights |
| 84 | lw_mix = 1.0; // assuming uniform grid density -- otherwise |
| 85 | |
| 86 | // Initial component in the mixture model |
| 87 | mat V0 = 1e-8 * eye ( dim + 1 ); |
| 88 | ARX A0; |
| 89 | A0.set_statistics ( dim, V0 ); //initial guess of Mix: |
| 90 | |
| 91 | Mix.init ( &A0, Smp_ex, Ncoms ); |
| 92 | //Preserve initial mixture for repetitive estimation via flattening |
| 93 | MixEF Mix_init ( Mix ); |
| 94 | |
| 95 | // ============= MAIN LOOP ================== |
| 96 | bool converged = false; |
| 97 | int niter = 0; |
| 98 | char dbg_str[100]; |
| 99 | |
| 100 | emix* Mpred = Mix.epredictor ( ); |
| 101 | vec Mix_pdf ( Npoints ); |
| 102 | while ( !converged ) { |
| 103 | //Re-estimate Mix |
| 104 | //Re-Initialize Mixture model |
| 105 | Mix.flatten ( &Mix_init ); |
| 106 | Mix.bayesB ( Smp_ex, w*Npoints ); |
| 107 | delete Mpred; |
| 108 | Mpred = Mix.epredictor ( ); // Allocation => must be deleted at the end!! |
| 109 | Mpred->set_rv ( rv ); //the predictor predicts rv of this merger |
| 110 | |
| 111 | // This will be active only later in iterations!!! |
| 112 | if ( 1. / sum_sqr ( w ) < effss_coef*Npoints ) { |
| 113 | // Generate new samples |
| 114 | eSmp.set_samples ( Mpred ); |
| 115 | for ( int i = 0; i < Npoints; i++ ) { |
| 116 | //////////// !!!!!!!!!!!!! |
| 117 | //if ( Smp ( i ) ( 2 ) <0 ) {Smp ( i ) ( 2 ) = 0.01; } |
| 118 | set_col_part ( Smp_ex, i, Smp ( i ) ); |
| 119 | //Importance of the mixture |
| 120 | //lw_mix ( i ) =Mix.logpred (Smp_ex.get_col(i) ); |
| 121 | lw_mix ( i ) = Mpred->evallog ( Smp ( i ) ); |
| 122 | } |
| 123 | if ( DBG ) { |
| 124 | cout << "Resampling =" << 1. / sum_sqr ( w ) << endl; |
| 125 | cout << Mix._e()->mean() << endl; |
| 126 | cout << sum ( Smp_ex, 2 ) / Npoints << endl; |
| 127 | cout << Smp_ex*Smp_ex.T() / Npoints << endl; |
| 128 | } |
| 129 | } |
| 130 | if ( DBG ) { |
| 131 | sprintf ( dbg_str, "Mpred_mean%d", niter ); |
| 132 | *dbg_file << Name ( dbg_str ) << Mpred->mean(); |
| 133 | sprintf ( dbg_str, "Mpred_var%d", niter ); |
| 134 | *dbg_file << Name ( dbg_str ) << Mpred->variance(); |
| 135 | |
| 136 | |
| 137 | sprintf ( dbg_str, "Mpdf%d", niter ); |
| 138 | for ( int i = 0; i < Npoints; i++ ) { |
| 139 | Mix_pdf ( i ) = Mix.logpred ( Smp_ex.get_col ( i ) ); |
| 140 | } |
| 141 | *dbg_file << Name ( dbg_str ) << Mix_pdf; |
| 142 | |
| 143 | sprintf ( dbg_str, "Smp%d", niter ); |
| 144 | *dbg_file << Name ( dbg_str ) << Smp_ex; |
| 145 | |
| 146 | } |
| 147 | //Importace weighting |
| 148 | for ( int i = 0; i < mpdfs.length(); i++ ) { |
| 149 | lw_src = 0.0; |
| 150 | //======== Same RVs =========== |
| 151 | //Split according to dependency in rvs |
| 152 | if ( mpdfs ( i )->dimension() == dim ) { |
| 153 | // no need for conditioning or marginalization |
| 154 | lw_src = mpdfs ( i )->e()->evallog_m ( Smp ); |
| 155 | } else { |
| 156 | // compute likelihood of marginal on the conditional variable |
| 157 | if ( mpdfs ( i )->dimensionc() > 0 ) { |
| 158 | // Make marginal on rvc_i |
| 159 | epdf* tmp_marg = Mpred->marginal ( mpdfs ( i )->_rvc() ); |
| 160 | //compute vector of lw_src |
| 161 | for ( int k = 0; k < Npoints; k++ ) { |
| 162 | // Here val of tmp_marg = cond of mpdfs(i) ==> calling dls->get_cond |
| 163 | lw_src ( k ) += tmp_marg->evallog ( dls ( i )->get_cond ( Smp ( k ) ) ); |
| 164 | } |
| 165 | delete tmp_marg; |
208 | | // it_assert_debug(std::isfinite(sum(lw_src)),"bad"); |
209 | | lW.set_row ( i, lw_src ); // do not divide by mix |
210 | | } |
211 | | lw = merger_base::merge_points ( lW ); //merge |
212 | | |
213 | | //Importance weighting |
214 | | lw -= lw_mix; // hoping that it is not numerically sensitive... |
215 | | w = exp ( lw-max ( lw ) ); |
216 | | |
217 | | //renormalize |
218 | | double sumw =sum ( w ); |
219 | | if ( std::isfinite ( sumw ) ) |
220 | | { |
221 | | w = w/sumw; |
222 | | } |
223 | | else |
224 | | { |
225 | | it_file itf ( "merg_err.it" ); |
226 | | itf << Name ( "w" ) << w; |
227 | | } |
228 | | |
229 | | if ( DBG ) |
230 | | { |
231 | | sprintf ( dbg_str,"lW%d",niter ); |
232 | | *dbg_file << Name ( dbg_str ) << lW; |
233 | | sprintf ( dbg_str,"w%d",niter ); |
234 | | *dbg_file << Name ( dbg_str ) << w; |
235 | | sprintf ( dbg_str,"lw_m%d",niter ); |
236 | | *dbg_file << Name ( dbg_str ) << lw_mix; |
237 | | } |
238 | | // ==== stopping rule === |
239 | | niter++; |
240 | | converged = ( niter>stop_niter ); |
241 | | } |
242 | | delete Mpred; |
| 190 | // Compute likelihood of the partial source |
| 191 | for ( int k = 0; k < Npoints; k++ ) { |
| 192 | mpdfs ( i )->condition ( dls ( i )->get_cond ( Smp ( k ) ) ); |
| 193 | lw_src ( k ) += mpdfs ( i )->e()->evallog ( dls ( i )->pushdown ( Smp ( k ) ) ); |
| 194 | } |
| 195 | |
| 196 | } |
| 197 | // it_assert_debug(std::isfinite(sum(lw_src)),"bad"); |
| 198 | lW.set_row ( i, lw_src ); // do not divide by mix |
| 199 | } |
| 200 | lw = merger_base::merge_points ( lW ); //merge |
| 201 | |
| 202 | //Importance weighting |
| 203 | lw -= lw_mix; // hoping that it is not numerically sensitive... |
| 204 | w = exp ( lw - max ( lw ) ); |
| 205 | |
| 206 | //renormalize |
| 207 | double sumw = sum ( w ); |
| 208 | if ( std::isfinite ( sumw ) ) { |
| 209 | w = w / sumw; |
| 210 | } else { |
| 211 | it_file itf ( "merg_err.it" ); |
| 212 | itf << Name ( "w" ) << w; |
| 213 | } |
| 214 | |
| 215 | if ( DBG ) { |
| 216 | sprintf ( dbg_str, "lW%d", niter ); |
| 217 | *dbg_file << Name ( dbg_str ) << lW; |
| 218 | sprintf ( dbg_str, "w%d", niter ); |
| 219 | *dbg_file << Name ( dbg_str ) << w; |
| 220 | sprintf ( dbg_str, "lw_m%d", niter ); |
| 221 | *dbg_file << Name ( dbg_str ) << lw_mix; |
| 222 | } |
| 223 | // ==== stopping rule === |
| 224 | niter++; |
| 225 | converged = ( niter > stop_niter ); |
| 226 | } |
| 227 | delete Mpred; |