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cpython/Lib/test/test_math.py
Mark Dickinson aa7633ab94 Merged revisions 65258,65292,65299,65308-65309,65315,65326 via svnmerge from 
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r65258 | mark.dickinson | 2008-07-27 08:15:29 +0100 (Sun, 27 Jul 2008) | 4 lines

  Remove math.sum tests related to overflow, special values, and behaviour
  near the extremes of the floating-point range.  (The behaviour of math.sum
  should be regarded as undefined in these cases.)
........
  r65292 | mark.dickinson | 2008-07-29 19:45:38 +0100 (Tue, 29 Jul 2008) | 4 lines

  More modifications to tests for math.sum:  replace the Python
  version of msum by a version using a different algorithm, and
  use the new float.fromhex method to specify test results exactly.
........
  r65299 | mark.dickinson | 2008-07-30 13:01:41 +0100 (Wed, 30 Jul 2008) | 5 lines

  Fix special-value handling for math.sum.
  Also minor cleanups to the code: fix tabbing, remove
  trailing whitespace, and reformat to fit into 80
  columns.
........
  r65308 | mark.dickinson | 2008-07-30 17:20:10 +0100 (Wed, 30 Jul 2008) | 2 lines

  Rename math.sum to math.fsum
........
  r65309 | mark.dickinson | 2008-07-30 17:25:16 +0100 (Wed, 30 Jul 2008) | 3 lines

  Replace math.sum with math.fsum in a couple of comments
  that were missed by r65308
........
  r65315 | mark.dickinson | 2008-07-30 21:23:15 +0100 (Wed, 30 Jul 2008) | 2 lines

  Add note about problems with math.fsum on x86 hardware.
........
  r65326 | mark.dickinson | 2008-07-31 15:48:32 +0100 (Thu, 31 Jul 2008) | 2 lines

  Rename testSum to testFsum and move it to proper place in test_math.py
........
2008-08-01 08:16:13 +00:00

892 lines
38 KiB
Python
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# Python test set -- math module
# XXXX Should not do tests around zero only
from test.support import run_unittest, verbose
import unittest
import math
import os
import sys
import random
eps = 1E-05
NAN = float('nan')
INF = float('inf')
NINF = float('-inf')
# locate file with test values
if __name__ == '__main__':
file = sys.argv[0]
else:
file = __file__
test_dir = os.path.dirname(file) or os.curdir
test_file = os.path.join(test_dir, 'cmath_testcases.txt')
def parse_testfile(fname):
"""Parse a file with test values
Empty lines or lines starting with -- are ignored
yields id, fn, arg_real, arg_imag, exp_real, exp_imag
"""
with open(fname) as fp:
for line in fp:
# skip comment lines and blank lines
if line.startswith('--') or not line.strip():
continue
lhs, rhs = line.split('->')
id, fn, arg_real, arg_imag = lhs.split()
rhs_pieces = rhs.split()
exp_real, exp_imag = rhs_pieces[0], rhs_pieces[1]
flags = rhs_pieces[2:]
yield (id, fn,
float(arg_real), float(arg_imag),
float(exp_real), float(exp_imag),
flags
)
class MathTests(unittest.TestCase):
def ftest(self, name, value, expected):
if abs(value-expected) > eps:
# Use %r instead of %f so the error message
# displays full precision. Otherwise discrepancies
# in the last few bits will lead to very confusing
# error messages
self.fail('%s returned %r, expected %r' %
(name, value, expected))
def testConstants(self):
self.ftest('pi', math.pi, 3.1415926)
self.ftest('e', math.e, 2.7182818)
def testAcos(self):
self.assertRaises(TypeError, math.acos)
self.ftest('acos(-1)', math.acos(-1), math.pi)
self.ftest('acos(0)', math.acos(0), math.pi/2)
self.ftest('acos(1)', math.acos(1), 0)
self.assertRaises(ValueError, math.acos, INF)
self.assertRaises(ValueError, math.acos, NINF)
self.assert_(math.isnan(math.acos(NAN)))
def testAcosh(self):
self.assertRaises(TypeError, math.acosh)
self.ftest('acosh(1)', math.acosh(1), 0)
self.ftest('acosh(2)', math.acosh(2), 1.3169578969248168)
self.assertRaises(ValueError, math.acosh, 0)
self.assertRaises(ValueError, math.acosh, -1)
self.assertEquals(math.acosh(INF), INF)
self.assertRaises(ValueError, math.acosh, NINF)
self.assert_(math.isnan(math.acosh(NAN)))
def testAsin(self):
self.assertRaises(TypeError, math.asin)
self.ftest('asin(-1)', math.asin(-1), -math.pi/2)
self.ftest('asin(0)', math.asin(0), 0)
self.ftest('asin(1)', math.asin(1), math.pi/2)
self.assertRaises(ValueError, math.asin, INF)
self.assertRaises(ValueError, math.asin, NINF)
self.assert_(math.isnan(math.asin(NAN)))
def testAsinh(self):
self.assertRaises(TypeError, math.asinh)
self.ftest('asinh(0)', math.asinh(0), 0)
self.ftest('asinh(1)', math.asinh(1), 0.88137358701954305)
self.ftest('asinh(-1)', math.asinh(-1), -0.88137358701954305)
self.assertEquals(math.asinh(INF), INF)
self.assertEquals(math.asinh(NINF), NINF)
self.assert_(math.isnan(math.asinh(NAN)))
def testAtan(self):
self.assertRaises(TypeError, math.atan)
self.ftest('atan(-1)', math.atan(-1), -math.pi/4)
self.ftest('atan(0)', math.atan(0), 0)
self.ftest('atan(1)', math.atan(1), math.pi/4)
self.ftest('atan(inf)', math.atan(INF), math.pi/2)
self.ftest('atan(-inf)', math.atan(NINF), -math.pi/2)
self.assert_(math.isnan(math.atan(NAN)))
def testAtanh(self):
self.assertRaises(TypeError, math.atan)
self.ftest('atanh(0)', math.atanh(0), 0)
self.ftest('atanh(0.5)', math.atanh(0.5), 0.54930614433405489)
self.ftest('atanh(-0.5)', math.atanh(-0.5), -0.54930614433405489)
self.assertRaises(ValueError, math.atanh, 1)
self.assertRaises(ValueError, math.atanh, -1)
self.assertRaises(ValueError, math.atanh, INF)
self.assertRaises(ValueError, math.atanh, NINF)
self.assert_(math.isnan(math.atanh(NAN)))
def testAtan2(self):
self.assertRaises(TypeError, math.atan2)
self.ftest('atan2(-1, 0)', math.atan2(-1, 0), -math.pi/2)
self.ftest('atan2(-1, 1)', math.atan2(-1, 1), -math.pi/4)
self.ftest('atan2(0, 1)', math.atan2(0, 1), 0)
self.ftest('atan2(1, 1)', math.atan2(1, 1), math.pi/4)
self.ftest('atan2(1, 0)', math.atan2(1, 0), math.pi/2)
# math.atan2(0, x)
self.ftest('atan2(0., -inf)', math.atan2(0., NINF), math.pi)
self.ftest('atan2(0., -2.3)', math.atan2(0., -2.3), math.pi)
self.ftest('atan2(0., -0.)', math.atan2(0., -0.), math.pi)
self.assertEqual(math.atan2(0., 0.), 0.)
self.assertEqual(math.atan2(0., 2.3), 0.)
self.assertEqual(math.atan2(0., INF), 0.)
self.assert_(math.isnan(math.atan2(0., NAN)))
# math.atan2(-0, x)
self.ftest('atan2(-0., -inf)', math.atan2(-0., NINF), -math.pi)
self.ftest('atan2(-0., -2.3)', math.atan2(-0., -2.3), -math.pi)
self.ftest('atan2(-0., -0.)', math.atan2(-0., -0.), -math.pi)
self.assertEqual(math.atan2(-0., 0.), -0.)
self.assertEqual(math.atan2(-0., 2.3), -0.)
self.assertEqual(math.atan2(-0., INF), -0.)
self.assert_(math.isnan(math.atan2(-0., NAN)))
# math.atan2(INF, x)
self.ftest('atan2(inf, -inf)', math.atan2(INF, NINF), math.pi*3/4)
self.ftest('atan2(inf, -2.3)', math.atan2(INF, -2.3), math.pi/2)
self.ftest('atan2(inf, -0.)', math.atan2(INF, -0.0), math.pi/2)
self.ftest('atan2(inf, 0.)', math.atan2(INF, 0.0), math.pi/2)
self.ftest('atan2(inf, 2.3)', math.atan2(INF, 2.3), math.pi/2)
self.ftest('atan2(inf, inf)', math.atan2(INF, INF), math.pi/4)
self.assert_(math.isnan(math.atan2(INF, NAN)))
# math.atan2(NINF, x)
self.ftest('atan2(-inf, -inf)', math.atan2(NINF, NINF), -math.pi*3/4)
self.ftest('atan2(-inf, -2.3)', math.atan2(NINF, -2.3), -math.pi/2)
self.ftest('atan2(-inf, -0.)', math.atan2(NINF, -0.0), -math.pi/2)
self.ftest('atan2(-inf, 0.)', math.atan2(NINF, 0.0), -math.pi/2)
self.ftest('atan2(-inf, 2.3)', math.atan2(NINF, 2.3), -math.pi/2)
self.ftest('atan2(-inf, inf)', math.atan2(NINF, INF), -math.pi/4)
self.assert_(math.isnan(math.atan2(NINF, NAN)))
# math.atan2(+finite, x)
self.ftest('atan2(2.3, -inf)', math.atan2(2.3, NINF), math.pi)
self.ftest('atan2(2.3, -0.)', math.atan2(2.3, -0.), math.pi/2)
self.ftest('atan2(2.3, 0.)', math.atan2(2.3, 0.), math.pi/2)
self.assertEqual(math.atan2(2.3, INF), 0.)
self.assert_(math.isnan(math.atan2(2.3, NAN)))
# math.atan2(-finite, x)
self.ftest('atan2(-2.3, -inf)', math.atan2(-2.3, NINF), -math.pi)
self.ftest('atan2(-2.3, -0.)', math.atan2(-2.3, -0.), -math.pi/2)
self.ftest('atan2(-2.3, 0.)', math.atan2(-2.3, 0.), -math.pi/2)
self.assertEqual(math.atan2(-2.3, INF), -0.)
self.assert_(math.isnan(math.atan2(-2.3, NAN)))
# math.atan2(NAN, x)
self.assert_(math.isnan(math.atan2(NAN, NINF)))
self.assert_(math.isnan(math.atan2(NAN, -2.3)))
self.assert_(math.isnan(math.atan2(NAN, -0.)))
self.assert_(math.isnan(math.atan2(NAN, 0.)))
self.assert_(math.isnan(math.atan2(NAN, 2.3)))
self.assert_(math.isnan(math.atan2(NAN, INF)))
self.assert_(math.isnan(math.atan2(NAN, NAN)))
def testCeil(self):
self.assertRaises(TypeError, math.ceil)
self.assertEquals(int, type(math.ceil(0.5)))
self.ftest('ceil(0.5)', math.ceil(0.5), 1)
self.ftest('ceil(1.0)', math.ceil(1.0), 1)
self.ftest('ceil(1.5)', math.ceil(1.5), 2)
self.ftest('ceil(-0.5)', math.ceil(-0.5), 0)
self.ftest('ceil(-1.0)', math.ceil(-1.0), -1)
self.ftest('ceil(-1.5)', math.ceil(-1.5), -1)
#self.assertEquals(math.ceil(INF), INF)
#self.assertEquals(math.ceil(NINF), NINF)
#self.assert_(math.isnan(math.ceil(NAN)))
class TestCeil:
def __ceil__(self):
return 42
class TestNoCeil:
pass
self.ftest('ceil(TestCeil())', math.ceil(TestCeil()), 42)
self.assertRaises(TypeError, math.ceil, TestNoCeil())
t = TestNoCeil()
t.__ceil__ = lambda *args: args
self.assertRaises(TypeError, math.ceil, t)
self.assertRaises(TypeError, math.ceil, t, 0)
if float.__getformat__("double").startswith("IEEE"):
def testCopysign(self):
self.assertRaises(TypeError, math.copysign)
# copysign should let us distinguish signs of zeros
self.assertEquals(copysign(1., 0.), 1.)
self.assertEquals(copysign(1., -0.), -1.)
self.assertEquals(copysign(INF, 0.), INF)
self.assertEquals(copysign(INF, -0.), NINF)
self.assertEquals(copysign(NINF, 0.), INF)
self.assertEquals(copysign(NINF, -0.), NINF)
# and of infinities
self.assertEquals(copysign(1., INF), 1.)
self.assertEquals(copysign(1., NINF), -1.)
self.assertEquals(copysign(INF, INF), INF)
self.assertEquals(copysign(INF, NINF), NINF)
self.assertEquals(copysign(NINF, INF), INF)
self.assertEquals(copysign(NINF, NINF), NINF)
self.assert_(math.isnan(copysign(NAN, 1.)))
self.assert_(math.isnan(copysign(NAN, INF)))
self.assert_(math.isnan(copysign(NAN, NINF)))
self.assert_(math.isnan(copysign(NAN, NAN)))
# copysign(INF, NAN) may be INF or it may be NINF, since
# we don't know whether the sign bit of NAN is set on any
# given platform.
self.assert_(math.isinf(copysign(INF, NAN)))
# similarly, copysign(2., NAN) could be 2. or -2.
self.assertEquals(abs(copysign(2., NAN)), 2.)
def testCos(self):
self.assertRaises(TypeError, math.cos)
self.ftest('cos(-pi/2)', math.cos(-math.pi/2), 0)
self.ftest('cos(0)', math.cos(0), 1)
self.ftest('cos(pi/2)', math.cos(math.pi/2), 0)
self.ftest('cos(pi)', math.cos(math.pi), -1)
try:
self.assert_(math.isnan(math.cos(INF)))
self.assert_(math.isnan(math.cos(NINF)))
except ValueError:
self.assertRaises(ValueError, math.cos, INF)
self.assertRaises(ValueError, math.cos, NINF)
self.assert_(math.isnan(math.cos(NAN)))
def testCosh(self):
self.assertRaises(TypeError, math.cosh)
self.ftest('cosh(0)', math.cosh(0), 1)
self.ftest('cosh(2)-2*cosh(1)**2', math.cosh(2)-2*math.cosh(1)**2, -1) # Thanks to Lambert
self.assertEquals(math.cosh(INF), INF)
self.assertEquals(math.cosh(NINF), INF)
self.assert_(math.isnan(math.cosh(NAN)))
def testDegrees(self):
self.assertRaises(TypeError, math.degrees)
self.ftest('degrees(pi)', math.degrees(math.pi), 180.0)
self.ftest('degrees(pi/2)', math.degrees(math.pi/2), 90.0)
self.ftest('degrees(-pi/4)', math.degrees(-math.pi/4), -45.0)
def testExp(self):
self.assertRaises(TypeError, math.exp)
self.ftest('exp(-1)', math.exp(-1), 1/math.e)
self.ftest('exp(0)', math.exp(0), 1)
self.ftest('exp(1)', math.exp(1), math.e)
self.assertEquals(math.exp(INF), INF)
self.assertEquals(math.exp(NINF), 0.)
self.assert_(math.isnan(math.exp(NAN)))
def testFabs(self):
self.assertRaises(TypeError, math.fabs)
self.ftest('fabs(-1)', math.fabs(-1), 1)
self.ftest('fabs(0)', math.fabs(0), 0)
self.ftest('fabs(1)', math.fabs(1), 1)
def testFactorial(self):
def fact(n):
result = 1
for i in range(1, int(n)+1):
result *= i
return result
values = list(range(10)) + [50, 100, 500]
random.shuffle(values)
for x in range(10):
for cast in (int, float):
self.assertEqual(math.factorial(cast(x)), fact(x), (x, fact(x), math.factorial(x)))
self.assertRaises(ValueError, math.factorial, -1)
self.assertRaises(ValueError, math.factorial, math.pi)
def testFloor(self):
self.assertRaises(TypeError, math.floor)
self.assertEquals(int, type(math.floor(0.5)))
self.ftest('floor(0.5)', math.floor(0.5), 0)
self.ftest('floor(1.0)', math.floor(1.0), 1)
self.ftest('floor(1.5)', math.floor(1.5), 1)
self.ftest('floor(-0.5)', math.floor(-0.5), -1)
self.ftest('floor(-1.0)', math.floor(-1.0), -1)
self.ftest('floor(-1.5)', math.floor(-1.5), -2)
# pow() relies on floor() to check for integers
# This fails on some platforms - so check it here
self.ftest('floor(1.23e167)', math.floor(1.23e167), 1.23e167)
self.ftest('floor(-1.23e167)', math.floor(-1.23e167), -1.23e167)
#self.assertEquals(math.ceil(INF), INF)
#self.assertEquals(math.ceil(NINF), NINF)
#self.assert_(math.isnan(math.floor(NAN)))
class TestFloor:
def __floor__(self):
return 42
class TestNoFloor:
pass
self.ftest('floor(TestFloor())', math.floor(TestFloor()), 42)
self.assertRaises(TypeError, math.floor, TestNoFloor())
t = TestNoFloor()
t.__floor__ = lambda *args: args
self.assertRaises(TypeError, math.floor, t)
self.assertRaises(TypeError, math.floor, t, 0)
def testFmod(self):
self.assertRaises(TypeError, math.fmod)
self.ftest('fmod(10,1)', math.fmod(10,1), 0)
self.ftest('fmod(10,0.5)', math.fmod(10,0.5), 0)
self.ftest('fmod(10,1.5)', math.fmod(10,1.5), 1)
self.ftest('fmod(-10,1)', math.fmod(-10,1), 0)
self.ftest('fmod(-10,0.5)', math.fmod(-10,0.5), 0)
self.ftest('fmod(-10,1.5)', math.fmod(-10,1.5), -1)
self.assert_(math.isnan(math.fmod(NAN, 1.)))
self.assert_(math.isnan(math.fmod(1., NAN)))
self.assert_(math.isnan(math.fmod(NAN, NAN)))
self.assertRaises(ValueError, math.fmod, 1., 0.)
self.assertRaises(ValueError, math.fmod, INF, 1.)
self.assertRaises(ValueError, math.fmod, NINF, 1.)
self.assertRaises(ValueError, math.fmod, INF, 0.)
self.assertEquals(math.fmod(3.0, INF), 3.0)
self.assertEquals(math.fmod(-3.0, INF), -3.0)
self.assertEquals(math.fmod(3.0, NINF), 3.0)
self.assertEquals(math.fmod(-3.0, NINF), -3.0)
self.assertEquals(math.fmod(0.0, 3.0), 0.0)
self.assertEquals(math.fmod(0.0, NINF), 0.0)
def testFrexp(self):
self.assertRaises(TypeError, math.frexp)
def testfrexp(name, result, expected):
(mant, exp), (emant, eexp) = result, expected
if abs(mant-emant) > eps or exp != eexp:
self.fail('%s returned %r, expected %r'%\
(name, result, expected))
testfrexp('frexp(-1)', math.frexp(-1), (-0.5, 1))
testfrexp('frexp(0)', math.frexp(0), (0, 0))
testfrexp('frexp(1)', math.frexp(1), (0.5, 1))
testfrexp('frexp(2)', math.frexp(2), (0.5, 2))
self.assertEquals(math.frexp(INF)[0], INF)
self.assertEquals(math.frexp(NINF)[0], NINF)
self.assert_(math.isnan(math.frexp(NAN)[0]))
def testFsum(self):
# math.fsum relies on exact rounding for correct operation.
# There's a known problem with IA32 floating-point that causes
# inexact rounding in some situations, and will cause the
# math.fsum tests below to fail; see issue #2937. On non IEEE
# 754 platforms, and on IEEE 754 platforms that exhibit the
# problem described in issue #2937, we simply skip the whole
# test.
if not float.__getformat__("double").startswith("IEEE"):
return
# on IEEE 754 compliant machines, both of the expressions
# below should round to 10000000000000002.0.
if 1e16+2.0 != 1e16+2.9999:
return
# Python version of math.fsum, for comparison. Uses a
# different algorithm based on frexp, ldexp and integer
# arithmetic.
from sys import float_info
mant_dig = float_info.mant_dig
etiny = float_info.min_exp - mant_dig
def msum(iterable):
"""Full precision summation. Compute sum(iterable) without any
intermediate accumulation of error. Based on the 'lsum' function
at http://code.activestate.com/recipes/393090/
"""
tmant, texp = 0, 0
for x in iterable:
mant, exp = math.frexp(x)
mant, exp = int(math.ldexp(mant, mant_dig)), exp - mant_dig
if texp > exp:
tmant <<= texp-exp
texp = exp
else:
mant <<= exp-texp
tmant += mant
# Round tmant * 2**texp to a float. The original recipe
# used float(str(tmant)) * 2.0**texp for this, but that's
# a little unsafe because str -> float conversion can't be
# relied upon to do correct rounding on all platforms.
tail = max(len(bin(abs(tmant)))-2 - mant_dig, etiny - texp)
if tail > 0:
h = 1 << (tail-1)
tmant = tmant // (2*h) + bool(tmant & h and tmant & 3*h-1)
texp += tail
return math.ldexp(tmant, texp)
test_values = [
([], 0.0),
([0.0], 0.0),
([1e100, 1.0, -1e100, 1e-100, 1e50, -1.0, -1e50], 1e-100),
([2.0**53, -0.5, -2.0**-54], 2.0**53-1.0),
([2.0**53, 1.0, 2.0**-100], 2.0**53+2.0),
([2.0**53+10.0, 1.0, 2.0**-100], 2.0**53+12.0),
([2.0**53-4.0, 0.5, 2.0**-54], 2.0**53-3.0),
([1./n for n in range(1, 1001)],
float.fromhex('0x1.df11f45f4e61ap+2')),
([(-1.)**n/n for n in range(1, 1001)],
float.fromhex('-0x1.62a2af1bd3624p-1')),
([1.7**(i+1)-1.7**i for i in range(1000)] + [-1.7**1000], -1.0),
([1e16, 1., 1e-16], 10000000000000002.0),
([1e16-2., 1.-2.**-53, -(1e16-2.), -(1.-2.**-53)], 0.0),
# exercise code for resizing partials array
([2.**n - 2.**(n+50) + 2.**(n+52) for n in range(-1074, 972, 2)] +
[-2.**1022],
float.fromhex('0x1.5555555555555p+970')),
]
for i, (vals, expected) in enumerate(test_values):
try:
actual = math.fsum(vals)
except OverflowError:
self.fail("test %d failed: got OverflowError, expected %r "
"for math.fsum(%.100r)" % (i, expected, vals))
except ValueError:
self.fail("test %d failed: got ValueError, expected %r "
"for math.fsum(%.100r)" % (i, expected, vals))
self.assertEqual(actual, expected)
from random import random, gauss, shuffle
for j in range(1000):
vals = [7, 1e100, -7, -1e100, -9e-20, 8e-20] * 10
s = 0
for i in range(200):
v = gauss(0, random()) ** 7 - s
s += v
vals.append(v)
shuffle(vals)
s = msum(vals)
self.assertEqual(msum(vals), math.fsum(vals))
def testHypot(self):
self.assertRaises(TypeError, math.hypot)
self.ftest('hypot(0,0)', math.hypot(0,0), 0)
self.ftest('hypot(3,4)', math.hypot(3,4), 5)
self.assertEqual(math.hypot(NAN, INF), INF)
self.assertEqual(math.hypot(INF, NAN), INF)
self.assertEqual(math.hypot(NAN, NINF), INF)
self.assertEqual(math.hypot(NINF, NAN), INF)
self.assert_(math.isnan(math.hypot(1.0, NAN)))
self.assert_(math.isnan(math.hypot(NAN, -2.0)))
def testLdexp(self):
self.assertRaises(TypeError, math.ldexp)
self.ftest('ldexp(0,1)', math.ldexp(0,1), 0)
self.ftest('ldexp(1,1)', math.ldexp(1,1), 2)
self.ftest('ldexp(1,-1)', math.ldexp(1,-1), 0.5)
self.ftest('ldexp(-1,1)', math.ldexp(-1,1), -2)
self.assertRaises(OverflowError, math.ldexp, 1., 1000000)
self.assertRaises(OverflowError, math.ldexp, -1., 1000000)
self.assertEquals(math.ldexp(1., -1000000), 0.)
self.assertEquals(math.ldexp(-1., -1000000), -0.)
self.assertEquals(math.ldexp(INF, 30), INF)
self.assertEquals(math.ldexp(NINF, -213), NINF)
self.assert_(math.isnan(math.ldexp(NAN, 0)))
# large second argument
for n in [10**5, 10**10, 10**20, 10**40]:
self.assertEquals(math.ldexp(INF, -n), INF)
self.assertEquals(math.ldexp(NINF, -n), NINF)
self.assertEquals(math.ldexp(1., -n), 0.)
self.assertEquals(math.ldexp(-1., -n), -0.)
self.assertEquals(math.ldexp(0., -n), 0.)
self.assertEquals(math.ldexp(-0., -n), -0.)
self.assert_(math.isnan(math.ldexp(NAN, -n)))
self.assertRaises(OverflowError, math.ldexp, 1., n)
self.assertRaises(OverflowError, math.ldexp, -1., n)
self.assertEquals(math.ldexp(0., n), 0.)
self.assertEquals(math.ldexp(-0., n), -0.)
self.assertEquals(math.ldexp(INF, n), INF)
self.assertEquals(math.ldexp(NINF, n), NINF)
self.assert_(math.isnan(math.ldexp(NAN, n)))
def testLog(self):
self.assertRaises(TypeError, math.log)
self.ftest('log(1/e)', math.log(1/math.e), -1)
self.ftest('log(1)', math.log(1), 0)
self.ftest('log(e)', math.log(math.e), 1)
self.ftest('log(32,2)', math.log(32,2), 5)
self.ftest('log(10**40, 10)', math.log(10**40, 10), 40)
self.ftest('log(10**40, 10**20)', math.log(10**40, 10**20), 2)
self.assertEquals(math.log(INF), INF)
self.assertRaises(ValueError, math.log, NINF)
self.assert_(math.isnan(math.log(NAN)))
def testLog1p(self):
self.assertRaises(TypeError, math.log1p)
self.ftest('log1p(1/e -1)', math.log1p(1/math.e-1), -1)
self.ftest('log1p(0)', math.log1p(0), 0)
self.ftest('log1p(e-1)', math.log1p(math.e-1), 1)
self.ftest('log1p(1)', math.log1p(1), math.log(2))
self.assertEquals(math.log1p(INF), INF)
self.assertRaises(ValueError, math.log1p, NINF)
self.assert_(math.isnan(math.log1p(NAN)))
n= 2**90
self.assertAlmostEquals(math.log1p(n), 62.383246250395075)
self.assertAlmostEquals(math.log1p(n), math.log1p(float(n)))
def testLog10(self):
self.assertRaises(TypeError, math.log10)
self.ftest('log10(0.1)', math.log10(0.1), -1)
self.ftest('log10(1)', math.log10(1), 0)
self.ftest('log10(10)', math.log10(10), 1)
self.assertEquals(math.log(INF), INF)
self.assertRaises(ValueError, math.log10, NINF)
self.assert_(math.isnan(math.log10(NAN)))
def testModf(self):
self.assertRaises(TypeError, math.modf)
def testmodf(name, result, expected):
(v1, v2), (e1, e2) = result, expected
if abs(v1-e1) > eps or abs(v2-e2):
self.fail('%s returned %r, expected %r'%\
(name, result, expected))
testmodf('modf(1.5)', math.modf(1.5), (0.5, 1.0))
testmodf('modf(-1.5)', math.modf(-1.5), (-0.5, -1.0))
self.assertEquals(math.modf(INF), (0.0, INF))
self.assertEquals(math.modf(NINF), (-0.0, NINF))
modf_nan = math.modf(NAN)
self.assert_(math.isnan(modf_nan[0]))
self.assert_(math.isnan(modf_nan[1]))
def testPow(self):
self.assertRaises(TypeError, math.pow)
self.ftest('pow(0,1)', math.pow(0,1), 0)
self.ftest('pow(1,0)', math.pow(1,0), 1)
self.ftest('pow(2,1)', math.pow(2,1), 2)
self.ftest('pow(2,-1)', math.pow(2,-1), 0.5)
self.assertEqual(math.pow(INF, 1), INF)
self.assertEqual(math.pow(NINF, 1), NINF)
self.assertEqual((math.pow(1, INF)), 1.)
self.assertEqual((math.pow(1, NINF)), 1.)
self.assert_(math.isnan(math.pow(NAN, 1)))
self.assert_(math.isnan(math.pow(2, NAN)))
self.assert_(math.isnan(math.pow(0, NAN)))
self.assertEqual(math.pow(1, NAN), 1)
# pow(0., x)
self.assertEqual(math.pow(0., INF), 0.)
self.assertEqual(math.pow(0., 3.), 0.)
self.assertEqual(math.pow(0., 2.3), 0.)
self.assertEqual(math.pow(0., 2.), 0.)
self.assertEqual(math.pow(0., 0.), 1.)
self.assertEqual(math.pow(0., -0.), 1.)
self.assertRaises(ValueError, math.pow, 0., -2.)
self.assertRaises(ValueError, math.pow, 0., -2.3)
self.assertRaises(ValueError, math.pow, 0., -3.)
self.assertRaises(ValueError, math.pow, 0., NINF)
self.assert_(math.isnan(math.pow(0., NAN)))
# pow(INF, x)
self.assertEqual(math.pow(INF, INF), INF)
self.assertEqual(math.pow(INF, 3.), INF)
self.assertEqual(math.pow(INF, 2.3), INF)
self.assertEqual(math.pow(INF, 2.), INF)
self.assertEqual(math.pow(INF, 0.), 1.)
self.assertEqual(math.pow(INF, -0.), 1.)
self.assertEqual(math.pow(INF, -2.), 0.)
self.assertEqual(math.pow(INF, -2.3), 0.)
self.assertEqual(math.pow(INF, -3.), 0.)
self.assertEqual(math.pow(INF, NINF), 0.)
self.assert_(math.isnan(math.pow(INF, NAN)))
# pow(-0., x)
self.assertEqual(math.pow(-0., INF), 0.)
self.assertEqual(math.pow(-0., 3.), -0.)
self.assertEqual(math.pow(-0., 2.3), 0.)
self.assertEqual(math.pow(-0., 2.), 0.)
self.assertEqual(math.pow(-0., 0.), 1.)
self.assertEqual(math.pow(-0., -0.), 1.)
self.assertRaises(ValueError, math.pow, -0., -2.)
self.assertRaises(ValueError, math.pow, -0., -2.3)
self.assertRaises(ValueError, math.pow, -0., -3.)
self.assertRaises(ValueError, math.pow, -0., NINF)
self.assert_(math.isnan(math.pow(-0., NAN)))
# pow(NINF, x)
self.assertEqual(math.pow(NINF, INF), INF)
self.assertEqual(math.pow(NINF, 3.), NINF)
self.assertEqual(math.pow(NINF, 2.3), INF)
self.assertEqual(math.pow(NINF, 2.), INF)
self.assertEqual(math.pow(NINF, 0.), 1.)
self.assertEqual(math.pow(NINF, -0.), 1.)
self.assertEqual(math.pow(NINF, -2.), 0.)
self.assertEqual(math.pow(NINF, -2.3), 0.)
self.assertEqual(math.pow(NINF, -3.), -0.)
self.assertEqual(math.pow(NINF, NINF), 0.)
self.assert_(math.isnan(math.pow(NINF, NAN)))
# pow(-1, x)
self.assertEqual(math.pow(-1., INF), 1.)
self.assertEqual(math.pow(-1., 3.), -1.)
self.assertRaises(ValueError, math.pow, -1., 2.3)
self.assertEqual(math.pow(-1., 2.), 1.)
self.assertEqual(math.pow(-1., 0.), 1.)
self.assertEqual(math.pow(-1., -0.), 1.)
self.assertEqual(math.pow(-1., -2.), 1.)
self.assertRaises(ValueError, math.pow, -1., -2.3)
self.assertEqual(math.pow(-1., -3.), -1.)
self.assertEqual(math.pow(-1., NINF), 1.)
self.assert_(math.isnan(math.pow(-1., NAN)))
# pow(1, x)
self.assertEqual(math.pow(1., INF), 1.)
self.assertEqual(math.pow(1., 3.), 1.)
self.assertEqual(math.pow(1., 2.3), 1.)
self.assertEqual(math.pow(1., 2.), 1.)
self.assertEqual(math.pow(1., 0.), 1.)
self.assertEqual(math.pow(1., -0.), 1.)
self.assertEqual(math.pow(1., -2.), 1.)
self.assertEqual(math.pow(1., -2.3), 1.)
self.assertEqual(math.pow(1., -3.), 1.)
self.assertEqual(math.pow(1., NINF), 1.)
self.assertEqual(math.pow(1., NAN), 1.)
# pow(x, 0) should be 1 for any x
self.assertEqual(math.pow(2.3, 0.), 1.)
self.assertEqual(math.pow(-2.3, 0.), 1.)
self.assertEqual(math.pow(NAN, 0.), 1.)
self.assertEqual(math.pow(2.3, -0.), 1.)
self.assertEqual(math.pow(-2.3, -0.), 1.)
self.assertEqual(math.pow(NAN, -0.), 1.)
# pow(x, y) is invalid if x is negative and y is not integral
self.assertRaises(ValueError, math.pow, -1., 2.3)
self.assertRaises(ValueError, math.pow, -15., -3.1)
# pow(x, NINF)
self.assertEqual(math.pow(1.9, NINF), 0.)
self.assertEqual(math.pow(1.1, NINF), 0.)
self.assertEqual(math.pow(0.9, NINF), INF)
self.assertEqual(math.pow(0.1, NINF), INF)
self.assertEqual(math.pow(-0.1, NINF), INF)
self.assertEqual(math.pow(-0.9, NINF), INF)
self.assertEqual(math.pow(-1.1, NINF), 0.)
self.assertEqual(math.pow(-1.9, NINF), 0.)
# pow(x, INF)
self.assertEqual(math.pow(1.9, INF), INF)
self.assertEqual(math.pow(1.1, INF), INF)
self.assertEqual(math.pow(0.9, INF), 0.)
self.assertEqual(math.pow(0.1, INF), 0.)
self.assertEqual(math.pow(-0.1, INF), 0.)
self.assertEqual(math.pow(-0.9, INF), 0.)
self.assertEqual(math.pow(-1.1, INF), INF)
self.assertEqual(math.pow(-1.9, INF), INF)
# pow(x, y) should work for x negative, y an integer
self.ftest('(-2.)**3.', math.pow(-2.0, 3.0), -8.0)
self.ftest('(-2.)**2.', math.pow(-2.0, 2.0), 4.0)
self.ftest('(-2.)**1.', math.pow(-2.0, 1.0), -2.0)
self.ftest('(-2.)**0.', math.pow(-2.0, 0.0), 1.0)
self.ftest('(-2.)**-0.', math.pow(-2.0, -0.0), 1.0)
self.ftest('(-2.)**-1.', math.pow(-2.0, -1.0), -0.5)
self.ftest('(-2.)**-2.', math.pow(-2.0, -2.0), 0.25)
self.ftest('(-2.)**-3.', math.pow(-2.0, -3.0), -0.125)
self.assertRaises(ValueError, math.pow, -2.0, -0.5)
self.assertRaises(ValueError, math.pow, -2.0, 0.5)
# the following tests have been commented out since they don't
# really belong here: the implementation of ** for floats is
# independent of the implemention of math.pow
#self.assertEqual(1**NAN, 1)
#self.assertEqual(1**INF, 1)
#self.assertEqual(1**NINF, 1)
#self.assertEqual(1**0, 1)
#self.assertEqual(1.**NAN, 1)
#self.assertEqual(1.**INF, 1)
#self.assertEqual(1.**NINF, 1)
#self.assertEqual(1.**0, 1)
def testRadians(self):
self.assertRaises(TypeError, math.radians)
self.ftest('radians(180)', math.radians(180), math.pi)
self.ftest('radians(90)', math.radians(90), math.pi/2)
self.ftest('radians(-45)', math.radians(-45), -math.pi/4)
def testSin(self):
self.assertRaises(TypeError, math.sin)
self.ftest('sin(0)', math.sin(0), 0)
self.ftest('sin(pi/2)', math.sin(math.pi/2), 1)
self.ftest('sin(-pi/2)', math.sin(-math.pi/2), -1)
try:
self.assert_(math.isnan(math.sin(INF)))
self.assert_(math.isnan(math.sin(NINF)))
except ValueError:
self.assertRaises(ValueError, math.sin, INF)
self.assertRaises(ValueError, math.sin, NINF)
self.assert_(math.isnan(math.sin(NAN)))
def testSinh(self):
self.assertRaises(TypeError, math.sinh)
self.ftest('sinh(0)', math.sinh(0), 0)
self.ftest('sinh(1)**2-cosh(1)**2', math.sinh(1)**2-math.cosh(1)**2, -1)
self.ftest('sinh(1)+sinh(-1)', math.sinh(1)+math.sinh(-1), 0)
self.assertEquals(math.sinh(INF), INF)
self.assertEquals(math.sinh(NINF), NINF)
self.assert_(math.isnan(math.sinh(NAN)))
def testSqrt(self):
self.assertRaises(TypeError, math.sqrt)
self.ftest('sqrt(0)', math.sqrt(0), 0)
self.ftest('sqrt(1)', math.sqrt(1), 1)
self.ftest('sqrt(4)', math.sqrt(4), 2)
self.assertEquals(math.sqrt(INF), INF)
self.assertRaises(ValueError, math.sqrt, NINF)
self.assert_(math.isnan(math.sqrt(NAN)))
def testTan(self):
self.assertRaises(TypeError, math.tan)
self.ftest('tan(0)', math.tan(0), 0)
self.ftest('tan(pi/4)', math.tan(math.pi/4), 1)
self.ftest('tan(-pi/4)', math.tan(-math.pi/4), -1)
try:
self.assert_(math.isnan(math.tan(INF)))
self.assert_(math.isnan(math.tan(NINF)))
except:
self.assertRaises(ValueError, math.tan, INF)
self.assertRaises(ValueError, math.tan, NINF)
self.assert_(math.isnan(math.tan(NAN)))
def testTanh(self):
self.assertRaises(TypeError, math.tanh)
self.ftest('tanh(0)', math.tanh(0), 0)
self.ftest('tanh(1)+tanh(-1)', math.tanh(1)+math.tanh(-1), 0)
self.ftest('tanh(inf)', math.tanh(INF), 1)
self.ftest('tanh(-inf)', math.tanh(NINF), -1)
self.assert_(math.isnan(math.tanh(NAN)))
# check that tanh(-0.) == -0. on IEEE 754 systems
if float.__getformat__("double").startswith("IEEE"):
self.assertEqual(math.tanh(-0.), -0.)
self.assertEqual(math.copysign(1., math.tanh(-0.)),
math.copysign(1., -0.))
def test_trunc(self):
self.assertEqual(math.trunc(1), 1)
self.assertEqual(math.trunc(-1), -1)
self.assertEqual(type(math.trunc(1)), int)
self.assertEqual(type(math.trunc(1.5)), int)
self.assertEqual(math.trunc(1.5), 1)
self.assertEqual(math.trunc(-1.5), -1)
self.assertEqual(math.trunc(1.999999), 1)
self.assertEqual(math.trunc(-1.999999), -1)
self.assertEqual(math.trunc(-0.999999), -0)
self.assertEqual(math.trunc(-100.999), -100)
class TestTrunc(object):
def __trunc__(self):
return 23
class TestNoTrunc(object):
pass
self.assertEqual(math.trunc(TestTrunc()), 23)
self.assertRaises(TypeError, math.trunc)
self.assertRaises(TypeError, math.trunc, 1, 2)
self.assertRaises(TypeError, math.trunc, TestNoTrunc())
# XXX Doesn't work because the method is looked up on
# the type only.
#t = TestNoTrunc()
#t.__trunc__ = lambda *args: args
#self.assertEquals((), math.trunc(t))
#self.assertRaises(TypeError, math.trunc, t, 0)
def testCopysign(self):
self.assertEqual(math.copysign(1, 42), 1.0)
self.assertEqual(math.copysign(0., 42), 0.0)
self.assertEqual(math.copysign(1., -42), -1.0)
self.assertEqual(math.copysign(3, 0.), 3.0)
self.assertEqual(math.copysign(4., -0.), -4.0)
def testIsnan(self):
self.assert_(math.isnan(float("nan")))
self.assert_(math.isnan(float("inf")* 0.))
self.failIf(math.isnan(float("inf")))
self.failIf(math.isnan(0.))
self.failIf(math.isnan(1.))
def testIsinf(self):
self.assert_(math.isinf(float("inf")))
self.assert_(math.isinf(float("-inf")))
self.assert_(math.isinf(1E400))
self.assert_(math.isinf(-1E400))
self.failIf(math.isinf(float("nan")))
self.failIf(math.isinf(0.))
self.failIf(math.isinf(1.))
# RED_FLAG 16-Oct-2000 Tim
# While 2.0 is more consistent about exceptions than previous releases, it
# still fails this part of the test on some platforms. For now, we only
# *run* test_exceptions() in verbose mode, so that this isn't normally
# tested.
if verbose:
def test_exceptions(self):
try:
x = math.exp(-1000000000)
except:
# mathmodule.c is failing to weed out underflows from libm, or
# we've got an fp format with huge dynamic range
self.fail("underflowing exp() should not have raised "
"an exception")
if x != 0:
self.fail("underflowing exp() should have returned 0")
# If this fails, probably using a strict IEEE-754 conforming libm, and x
# is +Inf afterwards. But Python wants overflows detected by default.
try:
x = math.exp(1000000000)
except OverflowError:
pass
else:
self.fail("overflowing exp() didn't trigger OverflowError")
# If this fails, it could be a puzzle. One odd possibility is that
# mathmodule.c's macros are getting confused while comparing
# Inf (HUGE_VAL) to a NaN, and artificially setting errno to ERANGE
# as a result (and so raising OverflowError instead).
try:
x = math.sqrt(-1.0)
except ValueError:
pass
else:
self.fail("sqrt(-1) didn't raise ValueError")
def test_testfile(self):
if not float.__getformat__("double").startswith("IEEE"):
return
for id, fn, ar, ai, er, ei, flags in parse_testfile(test_file):
# Skip if either the input or result is complex, or if
# flags is nonempty
if ai != 0. or ei != 0. or flags:
continue
if fn in ['rect', 'polar']:
# no real versions of rect, polar
continue
func = getattr(math, fn)
try:
result = func(ar)
except ValueError as exc:
message = (("Unexpected ValueError: %s\n " +
"in test %s:%s(%r)\n") % (exc.args[0], id, fn, ar))
self.fail(message)
except OverflowError:
message = ("Unexpected OverflowError in " +
"test %s:%s(%r)\n" % (id, fn, ar))
self.fail(message)
self.ftest("%s:%s(%r)" % (id, fn, ar), result, er)
def test_main():
from doctest import DocFileSuite
suite = unittest.TestSuite()
suite.addTest(unittest.makeSuite(MathTests))
suite.addTest(DocFileSuite("ieee754.txt"))
run_unittest(suite)
if __name__ == '__main__':
test_main()
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