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1 function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)
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2 % UPDATE_ESS Update the Expected Sufficient Statistics of a hhmm Q node.
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3 % function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, idden_bitv)
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4
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5 % Figure out the node numbers associated with each parent
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6 % e.g., D=4, d=3, Qps = all Qs above, so dom = [Q3(t-1) F4(t-1) F3(t-1) Q1(t) Q2(t) Q3(t)].
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7 % so self = Q3(t), old_self = Q3(t-1), CPD.Qps = [1 2], Qps = [Q1(t) Q2(t)]
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8 dom = fmarginal.domain;
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9 self = dom(end);
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10 old_self = dom(1);
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11 Qps = dom(length(dom)-length(CPD.Qps):end-1);
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12
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13 Qsz = CPD.Qsizes(CPD.d);
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14 Qpsz = prod(CPD.Qsizes(CPD.Qps));
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15
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16 % If some of the Q nodes are observed (which happens during supervised training)
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17 % the counts will only be non-zero in positions
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18 % consistent with the evidence. We put the computed marginal responsibilities
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19 % into the appropriate slots of the big counts array.
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20 % (Recall that observed discrete nodes only have a single effective value.)
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21 % (A more general, but much slower, way is to call add_evidence_to_dmarginal.)
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22 % We assume the F nodes are never observed.
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23
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24 obs_self = ~hidden_bitv(self);
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25 obs_Qps = (~isempty(Qps)) & (~any(hidden_bitv(Qps))); % we assume that all or none of the Q parents are observed
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26
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27 if obs_self
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28 self_val = evidence{self};
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29 oldself_val = evidence{old_self};
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30 end
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31
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32 if obs_Qps
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33 Qps_val = subv2ind(Qpsz, cat(1, evidence{Qps}));
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34 if Qps_val == 0
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35 keyboard
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36 end
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37 end
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38
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39 if CPD.d==1 % no Qps from above
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40 if ~CPD.F1toQ1 % no F from self
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41 % marg(Q1(t-1), F2(t-1), Q1(t))
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42 % F2(t-1) P(Q1(t)=j | Q1(t-1)=i)
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43 % 1 delta(i,j)
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44 % 2 transprob(i,j)
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45 if obs_self
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46 hor_counts = zeros(Qsz, Qsz);
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47 hor_counts(oldself_val, self_val) = fmarginal.T(2);
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48 else
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49 marg = reshape(fmarginal.T, [Qsz 2 Qsz]);
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50 hor_counts = squeeze(marg(:,2,:));
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51 end
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52 else
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53 % marg(Q1(t-1), F2(t-1), F1(t-1), Q1(t))
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54 % F2(t-1) F1(t-1) P(Qd(t)=j| Qd(t-1)=i)
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55 % ------------------------------------------------------
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56 % 1 1 delta(i,j)
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57 % 2 1 transprob(i,j)
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58 % 1 2 impossible
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59 % 2 2 startprob(j)
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60 if obs_self
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61 marg = myreshape(fmarginal.T, [1 2 2 1]);
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62 hor_counts = zeros(Qsz, Qsz);
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63 hor_counts(oldself_val, self_val) = marg(1,2,1,1);
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64 ver_counts = zeros(Qsz, 1);
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65 %ver_counts(self_val) = marg(1,2,2,1);
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66 ver_counts(self_val) = marg(1,2,2,1) + marg(1,1,2,1);
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67 else
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68 marg = reshape(fmarginal.T, [Qsz 2 2 Qsz]);
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69 hor_counts = squeeze(marg(:,2,1,:));
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70 %ver_counts = squeeze(sum(marg(:,2,2,:),1)); % sum over i
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71 ver_counts = squeeze(sum(marg(:,2,2,:),1)) + squeeze(sum(marg(:,1,2,:),1)); % sum i,b
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72 end
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73 end % F1toQ1
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74 else % d ~= 1
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75 if CPD.d < CPD.D % general case
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76 % marg(Qd(t-1), Fd+1(t-1), Fd(t-1), Qps(t), Qd(t))
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77 % Fd+1(t-1) Fd(t-1) P(Qd(t)=j| Qd(t-1)=i, Qps(t)=k)
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78 % ------------------------------------------------------
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79 % 1 1 delta(i,j)
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80 % 2 1 transprob(i,k,j)
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81 % 1 2 impossible
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82 % 2 2 startprob(k,j)
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83 if obs_Qps & obs_self
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84 marg = myreshape(fmarginal.T, [1 2 2 1 1]);
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85 k = 1;
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86 hor_counts = zeros(Qsz, Qpsz, Qsz);
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87 hor_counts(oldself_val, Qps_val, self_val) = marg(1, 2,1, k,1);
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88 ver_counts = zeros(Qpsz, Qsz);
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89 %ver_counts(Qps_val, self_val) = marg(1, 2,2, k,1);
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90 ver_counts(Qps_val, self_val) = marg(1, 2,2, k,1) + marg(1, 1,2, k,1);
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91 elseif obs_Qps & ~obs_self
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92 marg = myreshape(fmarginal.T, [Qsz 2 2 1 Qsz]);
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93 k = 1;
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94 hor_counts = zeros(Qsz, Qpsz, Qsz);
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95 hor_counts(:, Qps_val, :) = marg(:, 2,1, k,:);
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96 ver_counts = zeros(Qpsz, Qsz);
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97 %ver_counts(Qps_val, :) = sum(marg(:, 2,2, k,:), 1);
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98 ver_counts(Qps_val, :) = sum(marg(:, 2,2, k,:), 1) + sum(marg(:, 1,2, k,:), 1);
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99 elseif ~obs_Qps & obs_self
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100 error('not yet implemented')
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101 else % everything is hidden
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102 marg = reshape(fmarginal.T, [Qsz 2 2 Qpsz Qsz]);
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103 hor_counts = squeeze(marg(:,2,1,:,:)); % i,k,j
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104 %ver_counts = squeeze(sum(marg(:,2,2,:,:),1)); % sum over i
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105 ver_counts = squeeze(sum(marg(:,2,2,:,:),1)) + squeeze(sum(marg(:,1,2,:,:),1)); % sum over i,b
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106 end
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107 else % d == D, so no F from below
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108 % marg(QD(t-1), FD(t-1), Qps(t), QD(t))
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109 % FD(t-1) P(QD(t)=j | QD(t-1)=i, Qps(t)=k)
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110 % 1 transprob(i,k,j)
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111 % 2 startprob(k,j)
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112 if obs_Qps & obs_self
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113 marg = myreshape(fmarginal.T, [1 2 1 1]);
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114 k = 1;
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115 hor_counts = zeros(Qsz, Qpsz, Qsz);
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116 hor_counts(oldself_val, Qps_val, self_val) = marg(1, 1, k,1);
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117 ver_counts = zeros(Qpsz, Qsz);
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118 ver_counts(Qps_val, self_val) = marg(1, 2, k,1);
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119 elseif obs_Qps & ~obs_self
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120 marg = myreshape(fmarginal.T, [Qsz 2 1 Qsz]);
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121 k = 1;
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122 hor_counts = zeros(Qsz, Qpsz, Qsz);
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123 hor_counts(:, Qps_val, :) = marg(:, 1, k,:);
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124 ver_counts = zeros(Qpsz, Qsz);
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125 ver_counts(Qps_val, :) = sum(marg(:, 2, k, :), 1);
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126 elseif ~obs_Qps & obs_self
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127 error('not yet implemented')
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128 else % everything is hidden
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129 marg = reshape(fmarginal.T, [Qsz 2 Qpsz Qsz]);
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130 hor_counts = squeeze(marg(:,1,:,:));
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131 ver_counts = squeeze(sum(marg(:,2,:,:),1)); % sum over i
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132 end
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133 end
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134 end
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135
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136 CPD.sub_CPD_trans = update_ess_simple(CPD.sub_CPD_trans, hor_counts);
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137
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138 if ~isempty(CPD.sub_CPD_start)
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139 CPD.sub_CPD_start = update_ess_simple(CPD.sub_CPD_start, ver_counts);
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140 end
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141
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