def determine_param_orderings(predicate):
logger.debug("Determining ordering for: " + str(predicate))
def establish_relationship(value_pair, index_pair, op, cmp_map):
x,y = value_pair
i,k = index_pair
if not(cmp_map.has_key((i,k)) and cmp_map[(i,k)] == None):
if op(x,y):
if cmp_map.has_key((i,k)):
if op != cmp_map[(i,k)]:
cmp_map[(i,k)] = None
else:
cmp_map[(i,k)] = op
elif cmp_map.has_key((i,k)) and op == cmp_map[(i,k)]:
cmp_map[(i,k)] = None
logger.debug(str(cmp_map))
# end establish_relationship
v = UniqueVariableFactory()
type_map = {}
types = predicate.param_types
for i, type in zip(range(0, len(types)), types):
if not type_map.has_key(type):
type_map[type] = []
type_map[type].append(i)
pairs = []
for type in type_map.keys():
for x in choose(type_map[type], 2):
pairs.append(list(x))
cmp_map = {}
variables = v.next_variable_sequence(predicate.arity)
logger.debug("Calling: fol_bc_ask( %s )" % predicate(*variables))
for answer in fol_bc_ask([predicate(*variables)], {}):
logger.debug("Answer: " + str(answer))
for pair in pairs:
i,k = pair
x,y = answer[variables[i]], answer[variables[k]]
logger.debug("Comparing %s and %s." % (x, y))
try:
for op in [operator.lt, operator.gt, operator.eq]:
establish_relationship((x,y), (i,k), op, cmp_map)
except:
pass
return cmp_map
def foil_main(predicate, positive_tuples, negative_tuples, bk, ordering=None):
arity = predicate.arity
clauses = set([])
variable_factory = UniqueVariableFactory()
params = variable_factory.next_variable_sequence(predicate.arity,
prefix="PARAM_")
training_set = TrainingSet(predicate,
params,
positive_tuples,
negative_tuples)
while len(training_set.positive_examples) > 0:
head = tuple(training_set.variables)
for x in head: x.depth = 0
body = []
rule = MutableRule(predicate, head, body)
predicate.rules.append(rule)
construct_clause_recursive(predicate,
rule,
training_set,
bk,
variable_factory=variable_factory,
ordering=ordering)
