def get_best(preference_text, record_list):
'''
Get best records according to CPTheory (classical algorithm)
A record is best if it is not dominated by any other record
'''
# build theory
theory = build_cptheory(preference_text)
theory.split_rules()
if not theory.is_consistent():
return []
result, _ = get_best_and_worst(theory, record_list)
return result
def get_mtopk_partition(preference_text, record_list, k):
'''
Returns the top-k records (partition algorithm)
'''
theory = build_cptheory(preference_text)
theory.split_rules()
if not theory.is_consistent():
return []
# Build formulas
theory.build_formulas()
# Build comparisons
theory.build_comparisons()
# Apply algorithm
result = partition_mtopk(theory, record_list, k)
return result
def get_mbest_partition(preference_text, record_list):
'''
Get best records according to CPTheory (partition algorithm)
A record is best if it is not dominated by any other record
'''
theory = build_cptheory(preference_text)
theory.split_rules()
if not theory.is_consistent():
return []
# Build formulas
theory.build_formulas()
# Build comparisons from formulas
theory.build_comparisons()
# Apply partition algorithm
result = partition_mbest(theory, record_list)
return result
def get_topk(preference_text, record_list, k):
'''
Returns the top-k records with lowest level according to a cp-theory
'''
# build theory
theory = build_cptheory(preference_text)
theory.split_rules()
if not theory.is_consistent():
return []
worst_list = record_list
topk_list = []
while len(topk_list) < k and worst_list:
best_list, worst_list = get_best_and_worst(theory, worst_list)
topk_list += best_list
if len(topk_list) > k:
topk_list = topk_list[:k]
return topk_list