diff options
Diffstat (limited to 'Lib/test/test_statistics.py')
| -rw-r--r-- | Lib/test/test_statistics.py | 55 |
1 files changed, 46 insertions, 9 deletions
diff --git a/Lib/test/test_statistics.py b/Lib/test/test_statistics.py index 771a03e..bacb76a 100644 --- a/Lib/test/test_statistics.py +++ b/Lib/test/test_statistics.py @@ -2164,9 +2164,9 @@ class TestPStdev(VarianceStdevMixin, NumericTestCase): class TestSqrtHelpers(unittest.TestCase): - def test_isqrt_frac_rto(self): + def test_integer_sqrt_of_frac_rto(self): for n, m in itertools.product(range(100), range(1, 1000)): - r = statistics._isqrt_frac_rto(n, m) + r = statistics._integer_sqrt_of_frac_rto(n, m) self.assertIsInstance(r, int) if r*r*m == n: # Root is exact @@ -2177,7 +2177,7 @@ class TestSqrtHelpers(unittest.TestCase): self.assertTrue(m * (r - 1)**2 < n < m * (r + 1)**2) @requires_IEEE_754 - def test_sqrt_frac(self): + def test_float_sqrt_of_frac(self): def is_root_correctly_rounded(x: Fraction, root: float) -> bool: if not x: @@ -2204,22 +2204,59 @@ class TestSqrtHelpers(unittest.TestCase): denonimator: int = randrange(10 ** randrange(50)) + 1 with self.subTest(numerator=numerator, denonimator=denonimator): x: Fraction = Fraction(numerator, denonimator) - root: float = statistics._sqrt_frac(numerator, denonimator) + root: float = statistics._float_sqrt_of_frac(numerator, denonimator) self.assertTrue(is_root_correctly_rounded(x, root)) # Verify that corner cases and error handling match math.sqrt() - self.assertEqual(statistics._sqrt_frac(0, 1), 0.0) + self.assertEqual(statistics._float_sqrt_of_frac(0, 1), 0.0) with self.assertRaises(ValueError): - statistics._sqrt_frac(-1, 1) + statistics._float_sqrt_of_frac(-1, 1) with self.assertRaises(ValueError): - statistics._sqrt_frac(1, -1) + statistics._float_sqrt_of_frac(1, -1) # Error handling for zero denominator matches that for Fraction(1, 0) with self.assertRaises(ZeroDivisionError): - statistics._sqrt_frac(1, 0) + statistics._float_sqrt_of_frac(1, 0) # The result is well defined if both inputs are negative - self.assertAlmostEqual(statistics._sqrt_frac(-2, -1), math.sqrt(2.0)) + self.assertEqual(statistics._float_sqrt_of_frac(-2, -1), statistics._float_sqrt_of_frac(2, 1)) + + def test_decimal_sqrt_of_frac(self): + root: Decimal + numerator: int + denominator: int + + for root, numerator, denominator in [ + (Decimal('0.4481904599041192673635338663'), 200874688349065940678243576378, 1000000000000000000000000000000), # No adj + (Decimal('0.7924949131383786609961759598'), 628048187350206338833590574929, 1000000000000000000000000000000), # Adj up + (Decimal('0.8500554152289934068192208727'), 722594208960136395984391238251, 1000000000000000000000000000000), # Adj down + ]: + with decimal.localcontext(decimal.DefaultContext): + self.assertEqual(statistics._decimal_sqrt_of_frac(numerator, denominator), root) + + # Confirm expected root with a quad precision decimal computation + with decimal.localcontext(decimal.DefaultContext) as ctx: + ctx.prec *= 4 + high_prec_ratio = Decimal(numerator) / Decimal(denominator) + ctx.rounding = decimal.ROUND_05UP + high_prec_root = high_prec_ratio.sqrt() + with decimal.localcontext(decimal.DefaultContext): + target_root = +high_prec_root + self.assertEqual(root, target_root) + + # Verify that corner cases and error handling match Decimal.sqrt() + self.assertEqual(statistics._decimal_sqrt_of_frac(0, 1), 0.0) + with self.assertRaises(decimal.InvalidOperation): + statistics._decimal_sqrt_of_frac(-1, 1) + with self.assertRaises(decimal.InvalidOperation): + statistics._decimal_sqrt_of_frac(1, -1) + + # Error handling for zero denominator matches that for Fraction(1, 0) + with self.assertRaises(ZeroDivisionError): + statistics._decimal_sqrt_of_frac(1, 0) + + # The result is well defined if both inputs are negative + self.assertEqual(statistics._decimal_sqrt_of_frac(-2, -1), statistics._decimal_sqrt_of_frac(2, 1)) class TestStdev(VarianceStdevMixin, NumericTestCase): |