annotate toolboxes/FullBNT-1.0.7/bnt/CPDs/@softmax_CPD/convert_to_pot.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
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wolffd@0 1 function pot = convert_to_pot(CPD, pot_type, domain, evidence)
wolffd@0 2 % CONVERT_TO_POT Convert a softmax CPD to a potential
wolffd@0 3 % pots = convert_to_pot(CPD, pot_type, domain, evidence)
wolffd@0 4 %
wolffd@0 5 % pots = CPD evaluated using evidence(domain)
wolffd@0 6
wolffd@0 7 ncases = size(domain,2);
wolffd@0 8 assert(ncases==1); % not yet vectorized
wolffd@0 9
wolffd@0 10 sz = dom_sizes(CPD);
wolffd@0 11 ns = zeros(1, max(domain));
wolffd@0 12 ns(domain) = sz;
wolffd@0 13
wolffd@0 14 odom = domain(~isemptycell(evidence(domain)));
wolffd@0 15 T = convert_to_table(CPD, domain, evidence);
wolffd@0 16
wolffd@0 17 switch pot_type
wolffd@0 18 case 'u',
wolffd@0 19 pot = upot(domain, sz, T, 0*myones(sz));
wolffd@0 20 case 'd',
wolffd@0 21 ns(odom) = 1;
wolffd@0 22 pot = dpot(domain, ns(domain), T);
wolffd@0 23
wolffd@0 24 case {'c','g'},
wolffd@0 25 % Since we want the output to be a Gaussian, the whole family must be observed.
wolffd@0 26 % In other words, the potential is really just a constant.
wolffd@0 27 p = T;
wolffd@0 28 %p = prob_node(CPD, evidence(domain(end)), evidence(domain(1:end-1)));
wolffd@0 29 ns(domain) = 0;
wolffd@0 30 pot = cpot(domain, ns(domain), log(p));
wolffd@0 31
wolffd@0 32 case 'cg',
wolffd@0 33 T = T(:);
wolffd@0 34 ns(odom) = 1;
wolffd@0 35 can = cell(1, length(T));
wolffd@0 36 for i=1:length(T)
wolffd@0 37 can{i} = cpot([], [], log(T(i)));
wolffd@0 38 end
wolffd@0 39 ps = domain(1:end-1);
wolffd@0 40 dps = ps(CPD.dpndx);
wolffd@0 41 cps = ps(CPD.cpndx);
wolffd@0 42 ddom = [dps CPD.self];
wolffd@0 43 cdom = cps;
wolffd@0 44 pot = cgpot(ddom, cdom, ns, can);
wolffd@0 45
wolffd@0 46 case 'scg'
wolffd@0 47 T = T(:);
wolffd@0 48 ns(odom) = 1;
wolffd@0 49 pot_array = cell(1, length(T));
wolffd@0 50 for i=1:length(T)
wolffd@0 51 pot_array{i} = scgcpot([], [], T(i));
wolffd@0 52 end
wolffd@0 53 pot = scgpot(domain, [], [], ns, pot_array);
wolffd@0 54
wolffd@0 55 otherwise,
wolffd@0 56 error(['unrecognized pot type ' pot_type])
wolffd@0 57 end
wolffd@0 58