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Fix negative bandwidth test and add online code path test. (gh-118600)

This commit is contained in:
Raymond Hettinger 2024-05-05 12:29:23 -05:00 committed by GitHub
parent 9c13d9e37a
commit 5092ea238e
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2 changed files with 24 additions and 9 deletions
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5
Lib/statistics.py
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@ -1791,9 +1791,8 @@ def kde_random(data, h, kernel='normal', *, seed=None):
if h <= 0.0:
raise StatisticsError(f'Bandwidth h must be positive, not {h=!r}')
try:
kernel_invcdf = _kernel_invcdfs[kernel]
except KeyError:
kernel_invcdf = _kernel_invcdfs.get(kernel)
if kernel_invcdf is None:
raise StatisticsError(f'Unknown kernel name: {kernel!r}')
prng = _random.Random(seed)

28
Lib/test/test_statistics.py
View File

@ -2402,7 +2402,7 @@ class TestKDE(unittest.TestCase):
with self.assertRaises(StatisticsError):
kde(sample, h=0.0) # Zero bandwidth
with self.assertRaises(StatisticsError):
kde(sample, h=0.0) # Negative bandwidth
kde(sample, h=-1.0) # Negative bandwidth
with self.assertRaises(TypeError):
kde(sample, h='str') # Wrong bandwidth type
with self.assertRaises(StatisticsError):
@ -2426,6 +2426,14 @@ class TestKDE(unittest.TestCase):
self.assertEqual(f_hat(-1.0), 1/2)
self.assertEqual(f_hat(1.0), 1/2)
# Test online updates to data
data = [1, 2]
f_hat = kde(data, 5.0, 'triangular')
self.assertEqual(f_hat(100), 0.0)
data.append(100)
self.assertGreater(f_hat(100), 0.0)
def test_kde_kernel_invcdfs(self):
kernel_invcdfs = statistics._kernel_invcdfs
kde = statistics.kde
@ -2462,7 +2470,7 @@ class TestKDE(unittest.TestCase):
with self.assertRaises(TypeError):
kde_random(iter(sample), 1.5) # Data is not a sequence
with self.assertRaises(StatisticsError):
kde_random(sample, h=0.0) # Zero bandwidth
kde_random(sample, h=-1.0) # Zero bandwidth
with self.assertRaises(StatisticsError):
kde_random(sample, h=0.0) # Negative bandwidth
with self.assertRaises(TypeError):
@ -2474,10 +2482,10 @@ class TestKDE(unittest.TestCase):
h = 1.5
kernel = 'cosine'
prng = kde_random(sample, h, kernel)
self.assertEqual(prng.__name__, 'rand')
self.assertIn(kernel, prng.__doc__)
self.assertIn(repr(h), prng.__doc__)
rand = kde_random(sample, h, kernel)
self.assertEqual(rand.__name__, 'rand')
self.assertIn(kernel, rand.__doc__)
self.assertIn(repr(h), rand.__doc__)
# Approximate distribution test: Compare a random sample to the expected distribution
@ -2507,6 +2515,14 @@ class TestKDE(unittest.TestCase):
for x in xarr:
self.assertTrue(math.isclose(p_observed(x), p_expected(x), abs_tol=0.0005))
# Test online updates to data
data = [1, 2]
rand = kde_random(data, 5, 'triangular')
self.assertLess(max([rand() for i in range(5000)]), 10)
data.append(100)
self.assertGreater(max(rand() for i in range(5000)), 10)
class TestQuantiles(unittest.TestCase):