def run_bellkor(self, rs: RowSettings,
average_times: dict) -> Tuple[float, RowSettings]:
""" Bellkor Algorithm
:param rs: Row and Parameters
:param average_times: Dictionary of User -> Avg Time
:return: Prediction
"""
logger = logging.getLogger("BellKor.BellkorAlgorithm.run_bellkor")
# Find the difference from the Average Review data
delta = (rs.Time - average_times[rs.User])
# Find the Sign
sign = -1 if delta < 0 else 1
# Rescale
delta = abs(delta) / self.TIME_DIFF
# Find the 'deviation'
dev = sign * math.pow(delta, 0.4)
rs.set_dev(dev=dev)
# Find P
P = rs.p + rs.alpha_p * dev
# Calculate the Model Prediction
output = self.GLOBAL_MEAN + rs.b_u + (rs.alpha_u * dev) + rs.b_ut + \
(rs.b_i + rs.b_ibin) * (rs.c_u + rs.c_ut) + np.dot(rs.q.T, P)
logger.debug("Model Prediction: {}".format(output))
return output, rs
def test_row_settings(self):
# Setup
rs = RowSettings(user=1,
movie=100,
binval=20,
time=123123123123,
rating=4.5,
time_index=1,
**self.TEST_INPUTS)
# Assertions
self.assertEqual(rs.User, 1)
rs.set_dev(4.123123)
# Further Assetions
self.assertEqual(rs.Dev, 4.123123)
def get_row_settings(self, inputs):
""" Get the Row Settings
[Index, TimePeriod, User, Item, BaseRating]
:param inputs: Array Row
:return: RowSettings
"""
logger = logging.getLogger("BellKor.BellkorAlgorithm.get_row_settings")
# Row Values
user = int(inputs[2])
movie = int(inputs[3])
time_val = inputs[1]
binval = int((time_val - self.START_TIME) / (self.TIME_DIFF / 30))
# Get datetime Index
time_index = int(
time.mktime(
datetime.datetime.fromtimestamp(time_val).date().timetuple()))
time_index = int(self.TIME_MAP[time_index])
# Collate the Row Settings
rs = RowSettings(
user=user,
movie=movie,
rating=inputs[4],
binval=binval,
time=time_val,
time_index=time_index,
b_u=self.PARAMS.b_u[user],
alpha_u=self.PARAMS.alpha_u[user],
b_i=self.PARAMS.b_i[movie],
c_u=self.PARAMS.c_u[user],
b_ut=self.PARAMS.b_ut[user, time_index],
c_ut=self.PARAMS.c_ut[user, time_index],
b_ibin=self.PARAMS.b_ibin[movie - 1, binval],
p=self.PARAMS.p[user],
q=self.PARAMS.q[movie],
alpha_p=self.PARAMS.alpha_p[user],
)
logger.debug(f"Row Setting: {rs}")
return rs