def test_dot(self):
sv = SparseVector(4, {1: 1, 3: 2})
dv = DenseVector(array([1., 2., 3., 4.]))
lst = DenseVector([1, 2, 3, 4])
mat = array([[1., 2., 3., 4.], [1., 2., 3., 4.], [1., 2., 3., 4.],
[1., 2., 3., 4.]])
arr = pyarray.array('d', [0, 1, 2, 3])
self.assertEqual(10.0, sv.dot(dv))
self.assertTrue(array_equal(array([3., 6., 9., 12.]), sv.dot(mat)))
self.assertEqual(30.0, dv.dot(dv))
self.assertTrue(array_equal(array([10., 20., 30., 40.]), dv.dot(mat)))
self.assertEqual(30.0, lst.dot(dv))
self.assertTrue(array_equal(array([10., 20., 30., 40.]), lst.dot(mat)))
self.assertEqual(7.0, sv.dot(arr))
def test_dot(self):
sv = SparseVector(4, {1: 1, 3: 2})
dv = DenseVector(array([1., 2., 3., 4.]))
lst = DenseVector([1, 2, 3, 4])
mat = array([[1., 2., 3., 4.],
[1., 2., 3., 4.],
[1., 2., 3., 4.],
[1., 2., 3., 4.]])
arr = pyarray.array('d', [0, 1, 2, 3])
self.assertEqual(10.0, sv.dot(dv))
self.assertTrue(array_equal(array([3., 6., 9., 12.]), sv.dot(mat)))
self.assertEqual(30.0, dv.dot(dv))
self.assertTrue(array_equal(array([10., 20., 30., 40.]), dv.dot(mat)))
self.assertEqual(30.0, lst.dot(dv))
self.assertTrue(array_equal(array([10., 20., 30., 40.]), lst.dot(mat)))
self.assertEqual(7.0, sv.dot(arr))
def cosine_similarity(rates1: SparseVector, rates2: SparseVector) -> Decimal:
"""Compute cosine similarity
(https://en.wikipedia.org/wiki/Cosine_similarity)
Args:
rate1, rate2: pyspark.ml.linalg.SparseVector
rate values by each user
Returns:
decimal.Decimal
"""
dot_rates = Decimal(rates1.dot(rates2))
sq_rates1 = Decimal(np.sum(np.square(rates1.values)))
sq_rates2 = Decimal(np.sum(np.square(rates2.values)))
return dot_rates / (np.sqrt(sq_rates1) * np.sqrt(sq_rates2))