我刚学习Bayes Net Toolbox for MATLAB,我试过这个:
N = 4;
dag = zeros( N, N );
C = 1; S = 2; R = 3; W = 4;
dag( C, [R S] ) = 1;
dag( R, W ) = 1;
dag( S, W ) = 1;
discrete_nodes = 1:N;
node_sizes = [ 4 2 3 5];
onodes = [];
bNet = mk_bnet( dag, node_sizes, 'discrete', discrete_nodes, 'observed', onodes );
bNet.CPD{C} = tabular_CPD( bNet, C, 'CPT', [0.5 0.5] );
bNet.CPD{R} = tabular_CPD( bNet, R, 'CPT', [0.8 0.2 0.2 0.8 ] );
bNet.CPD{S} = tabular_CPD( bNet, S, 'CPT', [0.5 0.9 0.5 0.1] );
bNet.CPD{W} = tabular_CPD( bNet, W, 'CPT', [1 0.1 0.1 0.01 0 0.9 0.9 0.99 ] );
engine = jtree_inf_engine( bNet);
evidence = cell( 1,N );
evidence{W} = 2;
[engine, loglik] = enter_evidence( engine, evidence );
marg = marginal_nodes( engine, S );
marg.T
p = marg.T(2)
但它不起作用,并打印出来:
??? Error using ==> reshape
要重塑,元素的数量不得更改。
Error in ==> myreshape at 10
T = reshape(T, sizes(:)');
Error in ==> tabular_CPD.tabular_CPD at 90
CPD.CPT = myreshape(T, fam_sz);
Error in ==> bnet at 19
bNet.CPD{R} = tabular_CPD( bNet, R, 'CPT', [0.8 0.2 0.2 0.8 ] );
答案 0 :(得分:1)
我犯了一个错误:
node_sizes = [ 4 2 3 5];
应该是:
node_sizes = 2*ones(1,N);