To check out this repository please hg clone the following URL, or open the URL using EasyMercurial or your preferred Mercurial client.

Statistics Download as Zip
| Branch: | Revision:

root / _FullBNT / BNT / CPDs / @softmax_CPD / convert_to_pot.m @ 8:b5b38998ef3b

History | View | Annotate | Download (1.41 KB)

1
function pot = convert_to_pot(CPD, pot_type, domain, evidence)
2
% CONVERT_TO_POT Convert a softmax CPD to a potential
3
% pots = convert_to_pot(CPD, pot_type, domain, evidence)
4
%
5
% pots = CPD evaluated using evidence(domain)
6

    
7
ncases = size(domain,2);
8
assert(ncases==1); % not yet vectorized
9

    
10
sz = dom_sizes(CPD);
11
ns = zeros(1, max(domain));
12
ns(domain) = sz;
13

    
14
odom = domain(~isemptycell(evidence(domain)));
15
T = convert_to_table(CPD, domain, evidence);
16

    
17
switch pot_type
18
 case 'u',
19
  pot = upot(domain, sz, T, 0*myones(sz));  
20
 case 'd',
21
  ns(odom) = 1;
22
  pot = dpot(domain, ns(domain), T);          
23
 
24
 case {'c','g'},
25
  % Since we want the output to be a Gaussian, the whole family must be observed.
26
  % In other words, the potential is really just a constant.
27
  p = T;
28
  %p = prob_node(CPD, evidence(domain(end)), evidence(domain(1:end-1)));
29
  ns(domain) = 0;
30
  pot = cpot(domain, ns(domain), log(p));       
31
 
32
 case 'cg',
33
  T = T(:);
34
  ns(odom) = 1;
35
  can = cell(1, length(T));
36
  for i=1:length(T)
37
    can{i} = cpot([], [], log(T(i)));
38
  end
39
  ps = domain(1:end-1);
40
  dps = ps(CPD.dpndx);
41
  cps = ps(CPD.cpndx);
42
  ddom = [dps CPD.self];
43
  cdom = cps;
44
  pot = cgpot(ddom, cdom, ns, can);   
45
  
46
 case 'scg'
47
  T = T(:);
48
  ns(odom) = 1;
49
  pot_array = cell(1, length(T));
50
  for i=1:length(T)
51
    pot_array{i} = scgcpot([], [], T(i));
52
  end
53
  pot = scgpot(domain, [], [], ns, pot_array);   
54

    
55
 otherwise,
56
  error(['unrecognized pot type ' pot_type])
57
end
58