def run(self, table):
"""
:returns:
An instance of :class:`Quantiles`.
"""
column = table.columns[self._column_name]
data = column.values_without_nulls_sorted()
if not data:
return Quantiles([None for percentile in range(101)])
# Zeroth percentile is first datum
quantiles = [data[0]]
for percentile in range(1, 100):
k = len(data) * (float(percentile) / 100)
low = max(1, int(math.ceil(k)))
high = min(len(data), int(math.floor(k + 1)))
# No remainder
if low == high:
value = data[low - 1]
# Remainder
else:
value = (data[low - 1] + data[high - 1]) / 2
quantiles.append(value)
# Hundredth percentile is final datum
quantiles.append(data[-1])
return Quantiles(quantiles)
def run(self, column):
"""
:returns: An array of :class:`decimal.Decimal`.
"""
if column.aggregate(HasNulls()):
warn_null_calculation(self, column)
data = column.values_without_nulls_sorted()
# Zeroth percentile is first datum
quantiles = [data[0]]
for percentile in range(1, 100):
k = len(data) * (float(percentile) / 100)
low = max(1, int(math.ceil(k)))
high = min(len(data), int(math.floor(k + 1)))
# No remainder
if low == high:
value = data[low - 1]
# Remainder
else:
value = (data[low - 1] + data[high - 1]) / 2
quantiles.append(value)
# Hundredth percentile is final datum
quantiles.append(data[-1])
return Quantiles(quantiles)
def run(self, table):
"""
:returns:
An instance of :class:`Quantiles`.
"""
percentiles = Percentiles(self._column_name).run(table)
return Quantiles([percentiles[i] for i in range(0, 101, 25)])
class TestQuantiles(unittest.TestCase):
def setUp(self):
self.values = [0, 10, 20, 30, 40, 50]
self.quantiles = Quantiles(self.values)
def test_methods(self):
self.assertEqual(len(self.quantiles), 6)
self.assertEqual(self.quantiles[2], 20)
self.assertSequenceEqual(list(self.quantiles), self.values)
self.assertEqual(repr(self.quantiles), repr(self.values))
def test_locate(self):
self.assertEqual(self.quantiles.locate(25), 2)
self.assertEqual(self.quantiles.locate(40), 4)
with self.assertRaises(ValueError):
self.quantiles.locate(-10)
with self.assertRaises(ValueError):
self.quantiles.locate(51)
class TestQuantiles(unittest.TestCase):
def setUp(self):
self.values = [0, 10, 20, 30, 40, 50]
self.quantiles = Quantiles(self.values)
def test_methods(self):
self.assertEqual(len(self.quantiles), 6)
self.assertEqual(self.quantiles[2], 20)
self.assertSequenceEqual(list(self.quantiles), self.values)
self.assertEqual(repr(self.quantiles), repr(self.values))
def test_locate(self):
self.assertEqual(self.quantiles.locate(25), 2)
self.assertEqual(self.quantiles.locate(40), 4)
with self.assertRaises(ValueError):
self.quantiles.locate(-10)
with self.assertRaises(ValueError):
self.quantiles.locate(51)
def setUp(self):
self.values = [0, 10, 20, 30, 40, 50]
self.quantiles = Quantiles(self.values)
def setUp(self):
self.values = [0, 10, 20, 30, 40, 50]
self.quantiles = Quantiles(self.values)
def test_deciles_all_nulls(self):
self.assertEqual(
Deciles('four').run(self.table), Quantiles([None] * 11))
def test_quintiles_all_nulls(self):
self.assertEqual(
Quintiles('four').run(self.table), Quantiles([None] * 6))
def test_percentiles_all_nulls(self):
self.assertEqual(
Percentiles('four').run(self.table), Quantiles([None] * 101))
def run(self, column):
percentiles = column.aggregate(Percentiles())
return Quantiles([percentiles[i] for i in range(0, 101, 10)])
