symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_cmath.py
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_cmath.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,488 @@
+from test.test_support import run_unittest
+from test.test_math import parse_testfile, test_file
+import unittest
+import os, sys
+import cmath, math
+from cmath import phase, polar, rect, pi
+
+INF = float('inf')
+NAN = float('nan')
+
+complex_zeros = [complex(x, y) for x in [0.0, -0.0] for y in [0.0, -0.0]]
+complex_infinities = [complex(x, y) for x, y in [
+        (INF, 0.0),  # 1st quadrant
+        (INF, 2.3),
+        (INF, INF),
+        (2.3, INF),
+        (0.0, INF),
+        (-0.0, INF), # 2nd quadrant
+        (-2.3, INF),
+        (-INF, INF),
+        (-INF, 2.3),
+        (-INF, 0.0),
+        (-INF, -0.0), # 3rd quadrant
+        (-INF, -2.3),
+        (-INF, -INF),
+        (-2.3, -INF),
+        (-0.0, -INF),
+        (0.0, -INF), # 4th quadrant
+        (2.3, -INF),
+        (INF, -INF),
+        (INF, -2.3),
+        (INF, -0.0)
+        ]]
+complex_nans = [complex(x, y) for x, y in [
+        (NAN, -INF),
+        (NAN, -2.3),
+        (NAN, -0.0),
+        (NAN, 0.0),
+        (NAN, 2.3),
+        (NAN, INF),
+        (-INF, NAN),
+        (-2.3, NAN),
+        (-0.0, NAN),
+        (0.0, NAN),
+        (2.3, NAN),
+        (INF, NAN)
+        ]]
+
+def almostEqualF(a, b, rel_err=2e-15, abs_err = 5e-323):
+    """Determine whether floating-point values a and b are equal to within
+    a (small) rounding error.  The default values for rel_err and
+    abs_err are chosen to be suitable for platforms where a float is
+    represented by an IEEE 754 double.  They allow an error of between
+    9 and 19 ulps."""
+
+    # special values testing
+    if math.isnan(a):
+        return math.isnan(b)
+    if math.isinf(a):
+        return a == b
+
+    # if both a and b are zero, check whether they have the same sign
+    # (in theory there are examples where it would be legitimate for a
+    # and b to have opposite signs; in practice these hardly ever
+    # occur).
+    if not a and not b:
+        return math.copysign(1., a) == math.copysign(1., b)
+
+    # if a-b overflows, or b is infinite, return False.  Again, in
+    # theory there are examples where a is within a few ulps of the
+    # max representable float, and then b could legitimately be
+    # infinite.  In practice these examples are rare.
+    try:
+        absolute_error = abs(b-a)
+    except OverflowError:
+        return False
+    else:
+        return absolute_error <= max(abs_err, rel_err * abs(a))
+
+class CMathTests(unittest.TestCase):
+    # list of all functions in cmath
+    test_functions = [getattr(cmath, fname) for fname in [
+            'acos', 'acosh', 'asin', 'asinh', 'atan', 'atanh',
+            'cos', 'cosh', 'exp', 'log', 'log10', 'sin', 'sinh',
+            'sqrt', 'tan', 'tanh']]
+    # test first and second arguments independently for 2-argument log
+    test_functions.append(lambda x : cmath.log(x, 1729. + 0j))
+    test_functions.append(lambda x : cmath.log(14.-27j, x))
+
+    def setUp(self):
+        self.test_values = open(test_file)
+
+    def tearDown(self):
+        self.test_values.close()
+
+    def rAssertAlmostEqual(self, a, b, rel_err = 2e-15, abs_err = 5e-323):
+        """Check that two floating-point numbers are almost equal."""
+
+        # special values testing
+        if math.isnan(a):
+            if math.isnan(b):
+                return
+            self.fail("%s should be nan" % repr(b))
+
+        if math.isinf(a):
+            if a == b:
+                return
+            self.fail("finite result where infinity excpected: "
+                      "expected %s, got %s" % (repr(a), repr(b)))
+
+        if not a and not b:
+            if math.atan2(a, -1.) != math.atan2(b, -1.):
+                self.fail("zero has wrong sign: expected %s, got %s" %
+                          (repr(a), repr(b)))
+
+        # test passes if either the absolute error or the relative
+        # error is sufficiently small.  The defaults amount to an
+        # error of between 9 ulps and 19 ulps on an IEEE-754 compliant
+        # machine.
+
+        try:
+            absolute_error = abs(b-a)
+        except OverflowError:
+            pass
+        else:
+            if absolute_error <= max(abs_err, rel_err * abs(a)):
+                return
+        self.fail("%s and %s are not sufficiently close" % (repr(a), repr(b)))
+
+    def test_constants(self):
+        e_expected = 2.71828182845904523536
+        pi_expected = 3.14159265358979323846
+        self.rAssertAlmostEqual(cmath.pi, pi_expected, 9,
+            "cmath.pi is %s; should be %s" % (cmath.pi, pi_expected))
+        self.rAssertAlmostEqual(cmath.e,  e_expected, 9,
+            "cmath.e is %s; should be %s" % (cmath.e, e_expected))
+
+    def test_user_object(self):
+        # Test automatic calling of __complex__ and __float__ by cmath
+        # functions
+
+        # some random values to use as test values; we avoid values
+        # for which any of the functions in cmath is undefined
+        # (i.e. 0., 1., -1., 1j, -1j) or would cause overflow
+        cx_arg = 4.419414439 + 1.497100113j
+        flt_arg = -6.131677725
+
+        # a variety of non-complex numbers, used to check that
+        # non-complex return values from __complex__ give an error
+        non_complexes = ["not complex", 1, 5L, 2., None,
+                         object(), NotImplemented]
+
+        # Now we introduce a variety of classes whose instances might
+        # end up being passed to the cmath functions
+
+        # usual case: new-style class implementing __complex__
+        class MyComplex(object):
+            def __init__(self, value):
+                self.value = value
+            def __complex__(self):
+                return self.value
+
+        # old-style class implementing __complex__
+        class MyComplexOS:
+            def __init__(self, value):
+                self.value = value
+            def __complex__(self):
+                return self.value
+
+        # classes for which __complex__ raises an exception
+        class SomeException(Exception):
+            pass
+        class MyComplexException(object):
+            def __complex__(self):
+                raise SomeException
+        class MyComplexExceptionOS:
+            def __complex__(self):
+                raise SomeException
+
+        # some classes not providing __float__ or __complex__
+        class NeitherComplexNorFloat(object):
+            pass
+        class NeitherComplexNorFloatOS:
+            pass
+        class MyInt(object):
+            def __int__(self): return 2
+            def __long__(self): return 2L
+            def __index__(self): return 2
+        class MyIntOS:
+            def __int__(self): return 2
+            def __long__(self): return 2L
+            def __index__(self): return 2
+
+        # other possible combinations of __float__ and __complex__
+        # that should work
+        class FloatAndComplex(object):
+            def __float__(self):
+                return flt_arg
+            def __complex__(self):
+                return cx_arg
+        class FloatAndComplexOS:
+            def __float__(self):
+                return flt_arg
+            def __complex__(self):
+                return cx_arg
+        class JustFloat(object):
+            def __float__(self):
+                return flt_arg
+        class JustFloatOS:
+            def __float__(self):
+                return flt_arg
+
+        for f in self.test_functions:
+            # usual usage
+            self.assertEqual(f(MyComplex(cx_arg)), f(cx_arg))
+            self.assertEqual(f(MyComplexOS(cx_arg)), f(cx_arg))
+            # other combinations of __float__ and __complex__
+            self.assertEqual(f(FloatAndComplex()), f(cx_arg))
+            self.assertEqual(f(FloatAndComplexOS()), f(cx_arg))
+            self.assertEqual(f(JustFloat()), f(flt_arg))
+            self.assertEqual(f(JustFloatOS()), f(flt_arg))
+            # TypeError should be raised for classes not providing
+            # either __complex__ or __float__, even if they provide
+            # __int__, __long__ or __index__.  An old-style class
+            # currently raises AttributeError instead of a TypeError;
+            # this could be considered a bug.
+            self.assertRaises(TypeError, f, NeitherComplexNorFloat())
+            self.assertRaises(TypeError, f, MyInt())
+            self.assertRaises(Exception, f, NeitherComplexNorFloatOS())
+            self.assertRaises(Exception, f, MyIntOS())
+            # non-complex return value from __complex__ -> TypeError
+            for bad_complex in non_complexes:
+                self.assertRaises(TypeError, f, MyComplex(bad_complex))
+                self.assertRaises(TypeError, f, MyComplexOS(bad_complex))
+            # exceptions in __complex__ should be propagated correctly
+            self.assertRaises(SomeException, f, MyComplexException())
+            self.assertRaises(SomeException, f, MyComplexExceptionOS())
+
+    def test_input_type(self):
+        # ints and longs should be acceptable inputs to all cmath
+        # functions, by virtue of providing a __float__ method
+        for f in self.test_functions:
+            for arg in [2, 2L, 2.]:
+                self.assertEqual(f(arg), f(arg.__float__()))
+
+        # but strings should give a TypeError
+        for f in self.test_functions:
+            for arg in ["a", "long_string", "0", "1j", ""]:
+                self.assertRaises(TypeError, f, arg)
+
+    def test_cmath_matches_math(self):
+        # check that corresponding cmath and math functions are equal
+        # for floats in the appropriate range
+
+        # test_values in (0, 1)
+        test_values = [0.01, 0.1, 0.2, 0.5, 0.9, 0.99]
+
+        # test_values for functions defined on [-1., 1.]
+        unit_interval = test_values + [-x for x in test_values] + \
+            [0., 1., -1.]
+
+        # test_values for log, log10, sqrt
+        positive = test_values + [1.] + [1./x for x in test_values]
+        nonnegative = [0.] + positive
+
+        # test_values for functions defined on the whole real line
+        real_line = [0.] + positive + [-x for x in positive]
+
+        test_functions = {
+            'acos' : unit_interval,
+            'asin' : unit_interval,
+            'atan' : real_line,
+            'cos' : real_line,
+            'cosh' : real_line,
+            'exp' : real_line,
+            'log' : positive,
+            'log10' : positive,
+            'sin' : real_line,
+            'sinh' : real_line,
+            'sqrt' : nonnegative,
+            'tan' : real_line,
+            'tanh' : real_line}
+
+        for fn, values in test_functions.items():
+            float_fn = getattr(math, fn)
+            complex_fn = getattr(cmath, fn)
+            for v in values:
+                z = complex_fn(v)
+                self.rAssertAlmostEqual(float_fn(v), z.real)
+                self.assertEqual(0., z.imag)
+
+        # test two-argument version of log with various bases
+        for base in [0.5, 2., 10.]:
+            for v in positive:
+                z = cmath.log(v, base)
+                self.rAssertAlmostEqual(math.log(v, base), z.real)
+                self.assertEqual(0., z.imag)
+
+    def test_specific_values(self):
+        if not float.__getformat__("double").startswith("IEEE"):
+            return
+
+        def rect_complex(z):
+            """Wrapped version of rect that accepts a complex number instead of
+            two float arguments."""
+            return cmath.rect(z.real, z.imag)
+
+        def polar_complex(z):
+            """Wrapped version of polar that returns a complex number instead of
+            two floats."""
+            return complex(*polar(z))
+
+        for id, fn, ar, ai, er, ei, flags in parse_testfile(test_file):
+            arg = complex(ar, ai)
+            expected = complex(er, ei)
+            if fn == 'rect':
+                function = rect_complex
+            elif fn == 'polar':
+                function = polar_complex
+            else:
+                function = getattr(cmath, fn)
+            if 'divide-by-zero' in flags or 'invalid' in flags:
+                try:
+                    actual = function(arg)
+                except ValueError:
+                    continue
+                else:
+                    test_str = "%s: %s(complex(%r, %r))" % (id, fn, ar, ai)
+                    self.fail('ValueError not raised in test %s' % test_str)
+
+            if 'overflow' in flags:
+                try:
+                    actual = function(arg)
+                except OverflowError:
+                    continue
+                else:
+                    test_str = "%s: %s(complex(%r, %r))" % (id, fn, ar, ai)
+                    self.fail('OverflowError not raised in test %s' % test_str)
+
+            actual = function(arg)
+
+            if 'ignore-real-sign' in flags:
+                actual = complex(abs(actual.real), actual.imag)
+                expected = complex(abs(expected.real), expected.imag)
+            if 'ignore-imag-sign' in flags:
+                actual = complex(actual.real, abs(actual.imag))
+                expected = complex(expected.real, abs(expected.imag))
+
+            # for the real part of the log function, we allow an
+            # absolute error of up to 2e-15.
+            if fn in ('log', 'log10'):
+                real_abs_err = 2e-15
+            else:
+                real_abs_err = 5e-323
+
+            if not (almostEqualF(expected.real, actual.real,
+                                 abs_err = real_abs_err) and
+                    almostEqualF(expected.imag, actual.imag)):
+                error_message = (
+                    "%s: %s(complex(%r, %r))\n" % (id, fn, ar, ai) +
+                    "Expected: complex(%r, %r)\n" %
+                                    (expected.real, expected.imag) +
+                    "Received: complex(%r, %r)\n" %
+                                    (actual.real, actual.imag) +
+                    "Received value insufficiently close to expected value.")
+                self.fail(error_message)
+
+    def assertCISEqual(self, a, b):
+        eps = 1E-7
+        if abs(a[0] - b[0]) > eps or abs(a[1] - b[1]) > eps:
+            self.fail((a ,b))
+
+    def test_polar(self):
+        self.assertCISEqual(polar(0), (0., 0.))
+        self.assertCISEqual(polar(1.), (1., 0.))
+        self.assertCISEqual(polar(-1.), (1., pi))
+        self.assertCISEqual(polar(1j), (1., pi/2))
+        self.assertCISEqual(polar(-1j), (1., -pi/2))
+
+    def test_phase(self):
+        self.assertAlmostEqual(phase(0), 0.)
+        self.assertAlmostEqual(phase(1.), 0.)
+        self.assertAlmostEqual(phase(-1.), pi)
+        self.assertAlmostEqual(phase(-1.+1E-300j), pi)
+        self.assertAlmostEqual(phase(-1.-1E-300j), -pi)
+        self.assertAlmostEqual(phase(1j), pi/2)
+        self.assertAlmostEqual(phase(-1j), -pi/2)
+
+        # zeros
+        self.assertEqual(phase(complex(0.0, 0.0)), 0.0)
+        self.assertEqual(phase(complex(0.0, -0.0)), -0.0)
+        self.assertEqual(phase(complex(-0.0, 0.0)), pi)
+        self.assertEqual(phase(complex(-0.0, -0.0)), -pi)
+
+        # infinities
+        self.assertAlmostEqual(phase(complex(-INF, -0.0)), -pi)
+        self.assertAlmostEqual(phase(complex(-INF, -2.3)), -pi)
+        self.assertAlmostEqual(phase(complex(-INF, -INF)), -0.75*pi)
+        self.assertAlmostEqual(phase(complex(-2.3, -INF)), -pi/2)
+        self.assertAlmostEqual(phase(complex(-0.0, -INF)), -pi/2)
+        self.assertAlmostEqual(phase(complex(0.0, -INF)), -pi/2)
+        self.assertAlmostEqual(phase(complex(2.3, -INF)), -pi/2)
+        self.assertAlmostEqual(phase(complex(INF, -INF)), -pi/4)
+        self.assertEqual(phase(complex(INF, -2.3)), -0.0)
+        self.assertEqual(phase(complex(INF, -0.0)), -0.0)
+        self.assertEqual(phase(complex(INF, 0.0)), 0.0)
+        self.assertEqual(phase(complex(INF, 2.3)), 0.0)
+        self.assertAlmostEqual(phase(complex(INF, INF)), pi/4)
+        self.assertAlmostEqual(phase(complex(2.3, INF)), pi/2)
+        self.assertAlmostEqual(phase(complex(0.0, INF)), pi/2)
+        self.assertAlmostEqual(phase(complex(-0.0, INF)), pi/2)
+        self.assertAlmostEqual(phase(complex(-2.3, INF)), pi/2)
+        self.assertAlmostEqual(phase(complex(-INF, INF)), 0.75*pi)
+        self.assertAlmostEqual(phase(complex(-INF, 2.3)), pi)
+        self.assertAlmostEqual(phase(complex(-INF, 0.0)), pi)
+
+        # real or imaginary part NaN
+        for z in complex_nans:
+            self.assert_(math.isnan(phase(z)))
+
+    def test_abs(self):
+        # zeros
+        for z in complex_zeros:
+            self.assertEqual(abs(z), 0.0)
+
+        # infinities
+        for z in complex_infinities:
+            self.assertEqual(abs(z), INF)
+
+        # real or imaginary part NaN
+        self.assertEqual(abs(complex(NAN, -INF)), INF)
+        self.assert_(math.isnan(abs(complex(NAN, -2.3))))
+        self.assert_(math.isnan(abs(complex(NAN, -0.0))))
+        self.assert_(math.isnan(abs(complex(NAN, 0.0))))
+        self.assert_(math.isnan(abs(complex(NAN, 2.3))))
+        self.assertEqual(abs(complex(NAN, INF)), INF)
+        self.assertEqual(abs(complex(-INF, NAN)), INF)
+        self.assert_(math.isnan(abs(complex(-2.3, NAN))))
+        self.assert_(math.isnan(abs(complex(-0.0, NAN))))
+        self.assert_(math.isnan(abs(complex(0.0, NAN))))
+        self.assert_(math.isnan(abs(complex(2.3, NAN))))
+        self.assertEqual(abs(complex(INF, NAN)), INF)
+        self.assert_(math.isnan(abs(complex(NAN, NAN))))
+
+        # result overflows
+        if float.__getformat__("double").startswith("IEEE"):
+            self.assertRaises(OverflowError, abs, complex(1.4e308, 1.4e308))
+
+    def assertCEqual(self, a, b):
+        eps = 1E-7
+        if abs(a.real - b[0]) > eps or abs(a.imag - b[1]) > eps:
+            self.fail((a ,b))
+
+    def test_rect(self):
+        self.assertCEqual(rect(0, 0), (0, 0))
+        self.assertCEqual(rect(1, 0), (1., 0))
+        self.assertCEqual(rect(1, -pi), (-1., 0))
+        self.assertCEqual(rect(1, pi/2), (0, 1.))
+        self.assertCEqual(rect(1, -pi/2), (0, -1.))
+
+    def test_isnan(self):
+        self.failIf(cmath.isnan(1))
+        self.failIf(cmath.isnan(1j))
+        self.failIf(cmath.isnan(INF))
+        self.assert_(cmath.isnan(NAN))
+        self.assert_(cmath.isnan(complex(NAN, 0)))
+        self.assert_(cmath.isnan(complex(0, NAN)))
+        self.assert_(cmath.isnan(complex(NAN, NAN)))
+        self.assert_(cmath.isnan(complex(NAN, INF)))
+        self.assert_(cmath.isnan(complex(INF, NAN)))
+
+    def test_isinf(self):
+        self.failIf(cmath.isinf(1))
+        self.failIf(cmath.isinf(1j))
+        self.failIf(cmath.isinf(NAN))
+        self.assert_(cmath.isinf(INF))
+        self.assert_(cmath.isinf(complex(INF, 0)))
+        self.assert_(cmath.isinf(complex(0, INF)))
+        self.assert_(cmath.isinf(complex(INF, INF)))
+        self.assert_(cmath.isinf(complex(NAN, INF)))
+        self.assert_(cmath.isinf(complex(INF, NAN)))
+
+
+def test_main():
+    run_unittest(CMathTests)
+
+if __name__ == "__main__":
+    test_main()