yap-6.3/packages/ProbLog/problog_examples/learn_graph.pl

%%% -*- Mode: Prolog; -*-

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% ProbLog program describing a probabilistic graph
% (running example from ProbLog presentations)
% $Id: learn_graph.pl 4875 2010-10-05 15:28:35Z theo $
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% example for parameter learning with LeProbLog
%
% training and test examples are included at the end of the file
% query ?- do_learning(20).
% will run 20 iterations of learning with default settings
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

:- use_module(library(problog)).
:- use_module(library(problog_learning)).

%%%%
% background knowledge
%%%% 
% definition of acyclic path using list of visited nodes
path(X,Y) :- path(X,Y,[X],_).

path(X,X,A,A).
path(X,Y,A,R) :- 
  X\==Y, 
  edge(X,Z), 
  absent(Z,A), 
  path(Z,Y,[Z|A],R).

% using directed edges in both directions
edge(X,Y) :- dir_edge(Y,X).
edge(X,Y) :- dir_edge(X,Y).

% checking whether node hasn't been visited before
absent(_,[]).
absent(X,[Y|Z]):-X \= Y, absent(X,Z).

%%%%
% probabilistic facts 
% - probability represented by t/1 term means learnable parameter
% - argument of t/1 is real value (used to compare against in evaluation when known), use t(_) if unknown
%%%%
t(0.9)::dir_edge(1,2).
t(0.8)::dir_edge(2,3).
t(0.6)::dir_edge(3,4).
t(0.7)::dir_edge(1,6).
t(0.5)::dir_edge(2,6).
t(0.4)::dir_edge(6,5).
t(0.7)::dir_edge(5,3).
t(0.2)::dir_edge(5,4).

%%%%%%%%%%%%%%
% training examples of form example(ID,Query,DesiredProbability) 
%%%%%%%%%%%%%%

example(1,path(1,2),0.94).
example(2,path(1,3),0.81).
example(3,path(1,4),0.54).
example(4,path(1,5),0.70).
example(5,path(1,6),0.87).
example(6,path(2,3),0.85).
example(7,path(2,4),0.57).
example(8,path(2,5),0.72).
example(9,path(2,6),0.86).
example(10,path(3,4),0.66).
example(11,path(3,5),0.80).
example(12,path(3,6),0.75).
example(13,path(4,5),0.57).
example(14,path(4,6),0.51).
example(15,path(5,6),0.69).
% some examples for learning from proofs:
example(16,(dir_edge(2,3),dir_edge(2,6),dir_edge(6,5),dir_edge(5,4)),0.032).
example(17,(dir_edge(1,6),dir_edge(2,6),dir_edge(2,3),dir_edge(3,4)),0.168).
example(18,(dir_edge(5,3),dir_edge(5,4)),0.14).
example(19,(dir_edge(2,6),dir_edge(6,5)),0.2).
example(20,(dir_edge(1,2),dir_edge(2,3),dir_edge(3,4)),0.432).

%%%%%%%%%%%%%%
% test examples of form test_example(ID,Query,DesiredProbability) 
% note: ID namespace is shared with training example IDs
%%%%%%%%%%%%%%

test_example(21,path(2,1),0.94).
test_example(22,path(3,1),0.81).
test_example(23,path(4,1),0.54).
test_example(24,path(5,1),0.70).
test_example(25,path(6,1),0.87).
test_example(26,path(3,2),0.85).
test_example(27,path(4,2),0.57).
test_example(28,path(5,2),0.72).
test_example(29,path(6,2),0.86).
test_example(30,path(4,3),0.66).
test_example(31,path(5,3),0.80).
test_example(32,path(6,3),0.75).
test_example(33,path(5,4),0.57).
test_example(34,path(6,4),0.51).
test_example(35,path(6,5),0.69).