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| author | Christian Heimes <christian@cheimes.de> | 2008-01-03 22:32:26 (GMT) |
|---|---|---|
| committer | Christian Heimes <christian@cheimes.de> | 2008-01-03 22:32:26 (GMT) |
| commit | eebb79cc690e8ab02cb7f630cfbc046df2c0f4da (patch) | |
| tree | e6eae18d02015f5adb8535f3b69cf33e1ba9eb51 | |
| parent | 000a074c955a1964959ee908300ef49b41170a06 (diff) | |
| download | cpython-eebb79cc690e8ab02cb7f630cfbc046df2c0f4da.zip cpython-eebb79cc690e8ab02cb7f630cfbc046df2c0f4da.tar.gz cpython-eebb79cc690e8ab02cb7f630cfbc046df2c0f4da.tar.bz2 | |
Added copysign(x, y) function to the math module
| -rw-r--r-- | Doc/library/math.rst | 8 | ||||
| -rw-r--r-- | Lib/test/test_math.py | 7 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Modules/mathmodule.c | 11 |
4 files changed, 28 insertions, 1 deletions
diff --git a/Doc/library/math.rst b/Doc/library/math.rst index d0b03ed..36cdbce 100644 --- a/Doc/library/math.rst +++ b/Doc/library/math.rst @@ -31,6 +31,14 @@ Number-theoretic and representation functions: should return an :class:`Integral` value. +.. function:: copysign(x, y) + + Return *x* with the sign of *y*. ``copysign`` copies the sign bit of an IEEE + 754 float, ``copysign(1, -0.0)`` returns *-1.0*. + + ..versionadded:: 2.6 + + .. function:: fabs(x) Return the absolute value of *x*. diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py index d2da59b..f5bf1a3 100644 --- a/Lib/test/test_math.py +++ b/Lib/test/test_math.py @@ -229,6 +229,13 @@ class MathTests(unittest.TestCase): self.ftest('tanh(0)', math.tanh(0), 0) self.ftest('tanh(1)+tanh(-1)', math.tanh(1)+math.tanh(-1), 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.)) @@ -12,7 +12,8 @@ What's New in Python 2.6 alpha 1? Core and builtins ----------------- -- Issue #1640: Added math.isinf() and math.isnan() functions. +- Issue #1640: Added math.isinf(x), math.isnan(x) and math.copysign(x, y) + functions. - Issue #1635: Platform independent creation and representation of NaN and INF. float("nan"), float("inf") and float("-inf") now work on every diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c index 7540b5d..2c6262d 100644 --- a/Modules/mathmodule.c +++ b/Modules/mathmodule.c @@ -133,6 +133,14 @@ FUNC1(cos, cos, "cos(x)\n\nReturn the cosine of x (measured in radians).") FUNC1(cosh, cosh, "cosh(x)\n\nReturn the hyperbolic cosine of x.") +#if defined(MS_WINDOWS) || defined(HAVE_COPYSIGN) +#ifdef MS_WINDOWS +FUNC2(copysign, _copysign, +#else +FUNC2(copysign, copysign, +#endif + "copysign(x,y)\n\nReturn x with the sign of y."); +#endif FUNC1(exp, exp, "exp(x)\n\nReturn e raised to the power of x.") FUNC1(fabs, fabs, @@ -375,6 +383,9 @@ static PyMethodDef math_methods[] = { {"atan", math_atan, METH_O, math_atan_doc}, {"atan2", math_atan2, METH_VARARGS, math_atan2_doc}, {"ceil", math_ceil, METH_O, math_ceil_doc}, +#if defined(MS_WINDOWS) || defined(HAVE_COPYSIGN) + {"copysign", math_copysign, METH_VARARGS, math_copysign_doc}, +#endif {"cos", math_cos, METH_O, math_cos_doc}, {"cosh", math_cosh, METH_O, math_cosh_doc}, {"degrees", math_degrees, METH_O, math_degrees_doc}, |