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1 function mpe = find_mpe(engine, ev)
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2 % FIND_MPE Find the most probable explanation (Viterbi)
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3 % mpe = enter_evidence(engine, evidence, ...)
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4 %
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5 % evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or column vector)
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6 %
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7
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8 mpe = cell(size(ev));
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9 engine.tbn_engine = set_fields(engine.tbn_engine, 'maximize', 1);
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10
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11 T = size(ev, 2);
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12 f = cell(1,T);
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13 b = cell(1,T); % b{t}.clpot{c}
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14 ll = zeros(1,T);
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15 [f{1}, ll(1)] = fwd1(engine.tbn_engine, ev(:,1), 1);
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16 for t=2:T
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17 [f{t}, ll(t)] = fwd(engine.tbn_engine, f{t-1}, ev(:,t), t);
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18 end
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19
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20 if T==1
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21 [b{1}, mpe(:,1)] = backT_mpe(engine.tbn_engine, f{1}, ev(:,1), 1);
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22 else
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23 [b{T}, mpe(:,T)] = backT_mpe(engine.tbn_engine, f{T}, ev(:,T-1:T), T);
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24 for t=T-1:-1:2
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25 [b{t}, mpe(:,t)] = back_mpe(engine.tbn_engine, b{t+1}, f{t}, ev(:,t-1:t), t);
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26 end
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27 t = 1;
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28 [b{t}, mpe(:,t)] = back1_mpe(engine.tbn_engine, b{t+1}, f{t}, ev(:,1), t);
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29 end
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30 engine.b = b;
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31
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32
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33
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