def __init__(self):
self.logger = Logger().getLogger(__name__)
self.agdistis = AgdistisTableIdentifier()
self.propertyTableSearch = PropertyTableSearch()
class ConnectivityIdentifier(object):
def __init__(self):
self.logger = Logger().getLogger(__name__)
self.agdistis = AgdistisTableIdentifier()
self.propertyTableSearch = PropertyTableSearch()
def calculateConnectivity(self, relations, applyWeights):
numberOfColumns = len(relations[0])
numberOfRows = len(relations)
# If connected, then 1/numberOfColumns, otherwise 0
# Should be 1 if connected to all other columns
connectivity = [0] * numberOfColumns
# count all relations
for rowIndex, relation in enumerate(relations):
_weights = [0] * numberOfColumns
_connectivity = [0] * numberOfColumns
for columnIndex in relation:
score = 0
weight = 0
for otherColumnIndex in relation[columnIndex]:
if len(relation[columnIndex][otherColumnIndex]) > 0:
score += 1
weight += len(relation[columnIndex][otherColumnIndex])
score = float(score) / numberOfColumns
_connectivity[columnIndex] += score
_weights[columnIndex] += weight
# Apply weights
maximumWeight = max(_weights)
for columnIndex, w in enumerate(_weights):
if applyWeights:
if maximumWeight == 0:
connectivity[columnIndex] += _connectivity[columnIndex]
else:
connectivity[columnIndex] += _connectivity[columnIndex] * (float(w) / maximumWeight)
else:
connectivity[columnIndex] += _connectivity[columnIndex]
# Normalize by number of rows
for columnIndex, _connectivity in enumerate(connectivity):
connectivity[columnIndex] = float(_connectivity) / numberOfRows
return connectivity
def identifySubjectColumn(self, table, applyWeights=False, connectivityFloor=0, connectivityCeil=100):
connectivity = self.getConnectivity(table, applyWeights)
connectivity = [
_connectivity if _connectivity > connectivityFloor and _connectivity < connectivityCeil else 0
for _connectivity in connectivity
]
# Return column with maximum support
if max(connectivity) == 0:
return -1
else:
return connectivity.index(max(connectivity))
def getConnectivity(self, table, applyWeights=False):
entities = self.agdistis.disambiguateTable(table)
relations = self.propertyTableSearch.findRelationsForTable(table, entities)
return self.calculateConnectivity(relations, applyWeights)
