Question

我正在尝试使用Matlab中的贝叶斯网络工具箱（BNT）创建动态贝叶斯网络。我已经仔细阅读了本教程，最后得到了以下代码：

T=2;
names = {'X1', 'X2', 'X3', 'X4', 'X5', 'X6', 'X7', 'X8', 'X9', 'X10', 'X11', 'X12'};
ss = length(names);
onodes=[1 2 3 4 5 6 7 8 9 10 11 12];
intrac = {
  'X1', 'X2';
  'X3', 'X4';
  'X6', 'X7';
  'X7', 'X8';
  'X10', 'X11';
  'X10', 'X12';
  'X11', 'X12';
  };
[intra, names] = mk_adj_mat(intrac, names, 1);
interc = {
   'X1', 'X1';
   'X2', 'X2';
   'X3', 'X3';
   'X4', 'X4';
   'X5', 'X5';
   'X6', 'X6';
   'X7', 'X7';
   'X8', 'X8';
   'X9', 'X9';
   'X10', 'X10';
   'X11', 'X11';
   'X12', 'X12';
   };
inter = mk_adj_mat(interc, names, 0);  
dnodes = 1:ss; 
ns = [3 3 3 2 4 5 2 2 4 5 4 5]; 
ns(stringmatch('X1',names))=3;
ns(stringmatch('X2',names))=3;
ns(stringmatch('X3',names))=3;
ns(stringmatch('X4',names))=2;
ns(stringmatch('X5',names))=4;
ns(stringmatch('X6',names))=5;
ns(stringmatch('X7',names))=2;
ns(stringmatch('X8',names))=2;
ns(stringmatch('X9',names))=4;
ns(stringmatch('X10',names))=5;
ns(stringmatch('X11',names))=4;
ns(stringmatch('X12',names))=5;

bnet = mk_dbn(intra, inter, ns, 'discrete', dnodes);
for i=1:2*ss
  bnet.CPD{i} = tabular_CPD(bnet, i);
end
allcases=importdata('Myfile.txt',',');
ncases = size(allcases.data,1);
cases = cell(1, ncases);
for i=1:ncases
  cases{i} = cell(ss,T);
  dataentry=allcases.data(i,:);
  ev=uint8([dataentry(1:12)' dataentry(13:24)']);
  cases{i} = num2cell(ev);
end
engine2 = smoother_engine(jtree_2TBN_inf_engine(bnet));
%engine2 = jtree_2TBN_inf_engine(bnet);
[bnt, LL, engine2] = learn_params_dbn_em(engine2, cases, 'max_iter', 20);

当我尝试运行它时，会出现以下错误：

Subscript indices must either be real positive integers or logicals.

Error in discrete_CPD/convert_to_table (line 14)
T = CPT(index{:});

Error in discrete_CPD/convert_to_pot (line 20)
   T = convert_to_table(CPD, domain, evidence);


Error in jtree_2TBN_inf_engine/fwd1 (line 11)
  CPDpot{n} = convert_to_pot(bnet.CPD{e}, engine.pot_type, fam(:), ev);

Error in smoother_engine/enter_evidence (line 12)
[f{1}, ll(1)] = fwd1(engine.tbn_engine, ev(:,1), 1);

Error in learn_params_dbn_em>EM_step (line 131)
  [engine, ll] = enter_evidence(engine, evidence);

Error in learn_params_dbn_em (line 82)
  [engine, loglik, logpost] = EM_step(engine, evidence, temperature);

有人可以帮我解决这个错误吗？我认为这与我创建表格CPD的方式有关，因为当我查看bnet中的CPD时，它们都是1 * 1表格。我的CPD创建方式与教程相同。提前谢谢！

Answer 1

问题解决了，数据集有问题。在我的数据集中，我使用一个单元格表示所有数据条目，而不是每个数据条目使用一个单元格。现在代码工作正常。

利用BNT学习动态贝叶斯网络的参数

1 个答案: