diff options
Diffstat (limited to 'sourcecodes/bnt-master/BNT/CPDs/@discrete_CPD/prob_node.m')
| -rw-r--r-- | sourcecodes/bnt-master/BNT/CPDs/@discrete_CPD/prob_node.m | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/BNT/CPDs/@discrete_CPD/prob_node.m b/sourcecodes/bnt-master/BNT/CPDs/@discrete_CPD/prob_node.m new file mode 100644 index 00000000..275870c8 --- /dev/null +++ b/sourcecodes/bnt-master/BNT/CPDs/@discrete_CPD/prob_node.m @@ -0,0 +1,81 @@ +function [P, p] = prob_node(CPD, self_ev, pev) +% PROB_NODE Compute prod_m P(x(i,m)| x(pi_i,m), theta_i) for node i (discrete) +% [P, p] = prob_node(CPD, self_ev, pev) +% +% self_ev(m) is the evidence on this node in case m. +% pev(i,m) is the evidence on the i'th parent in case m (if there are any parents). +% (These may also be cell arrays.) +% +% p(m) = P(x(i,m)| x(pi_i,m), theta_i) +% P = prod p(m) + +if iscell(self_ev), usecell = 1; else usecell = 0; end + +ncases = length(self_ev); +sz = dom_sizes(CPD); + +nparents = length(sz)-1; +if nparents == 0 + assert(isempty(pev)); +else + assert(isequal(size(pev), [nparents ncases])); +end + +n = length(sz); +dom = 1:n; +p = zeros(1, ncases); +if isa(CPD, 'tabular_CPD') + % speed up by looking up CPT using index Zhang Yimin 2001-12-31 + if usecell + if nparents == 0 + data = [cell2num(self_ev)]; + else + data = [cell2num(pev); cell2num(self_ev)]; + end + else + if nparents == 0 + data = [self_ev]; + else + data = [pev; self_ev]; + end + end + + indices = subv2ind(sz, data'); % each row of data' is a case + + CPT=CPD_to_CPT(CPD); + p = CPT(indices); + + %get the prob list + %cpt_size = prod(sz); + %prob_list=reshape(CPT, cpt_size, 1); + %for m=1:ncases %here we assume we get evidence for node and all its parents + % idx=indices(m); + % p(m)=prob_list(idx); + %end + +else % eg. softmax + + for m=1:ncases + if usecell + if nparents == 0 + evidence = {self_ev{m}}; + else + evidence = cell(1,n); + evidence(1:n-1) = pev(:,m); + evidence(n) = self_ev(m); + end + else + if nparents == 0 + evidence = num2cell(self_ev(m)); + else + evidence = num2cell([pev(:,m)', self_ev(m)]); + end + end + T = convert_to_table(CPD, dom, evidence); + p(m) = T; + end +end + +P = prod(p); + + |
