I finally got the time to update and merge Mark's and my trunk-math branch. The patch is collaborated work of Mark Dickinson and me. It was mostly done a few months ago. The patch fixes a lot of loose ends and edge cases related to operations with NaN, INF, very small values and complex math.
The patch also adds acosh, asinh, atanh, log1p and copysign to all platforms. Finally it fixes differences between platforms like different results or exceptions for edge cases. Have fun :)
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 47ebadb..ad36f92 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -139,6 +139,14 @@
*base* argument added.
+.. function:: log1p(x)
+
+ Return the natural logarithm of *1+x* (base *e*). The
+ result is calculated in a way which is accurate for *x* near zero.
+
+ .. versionadded:: 2.6
+
+
.. function:: log10(x)
Return the base-10 logarithm of *x*.
@@ -146,7 +154,11 @@
.. function:: pow(x, y)
- Return ``x**y``.
+ Return ``x**y``. ``1.0**y`` returns *1.0*, even for ``1.0**nan``. ``0**y``
+ returns *0.* for all positive *y*, *0* and *NAN*.
+
+ .. versionchanged:: 2.6
+ The outcome of ``1**nan`` and ``0**nan`` was undefined.
.. function:: sqrt(x)
@@ -197,6 +209,13 @@
Return the sine of *x* radians.
+.. function:: asinh(x)
+
+ Return the inverse hyperbolic sine of *x*, in radians.
+
+ .. versionadded:: 2.6
+
+
.. function:: tan(x)
Return the tangent of *x* radians.
@@ -221,6 +240,13 @@
Return the hyperbolic cosine of *x*.
+.. function:: acosh(x)
+
+ Return the inverse hyperbolic cosine of *x*, in radians.
+
+ .. versionadded:: 2.6
+
+
.. function:: sinh(x)
Return the hyperbolic sine of *x*.
@@ -230,6 +256,14 @@
Return the hyperbolic tangent of *x*.
+
+.. function:: atanh(x)
+
+ Return the inverse hyperbolic tangent of *x*, in radians.
+
+ .. versionadded:: 2.6
+
+
The module also defines two mathematical constants:
@@ -242,6 +276,7 @@
The mathematical constant *e*.
+
.. note::
The :mod:`math` module consists mostly of thin wrappers around the platform C
@@ -255,9 +290,17 @@
:exc:`OverflowError` isn't defined, and in cases where ``math.log(0)`` raises
:exc:`OverflowError`, ``math.log(0L)`` may raise :exc:`ValueError` instead.
+ All functions return a quite *NaN* if at least one of the args is *NaN*.
+ Signaling *NaN*s raise an exception. The exception type still depends on the
+ platform and libm implementation. It's usually :exc:`ValueError` for *EDOM*
+ and :exc:`OverflowError` for errno *ERANGE*.
+
+ ..versionchanged:: 2.6
+ In earlier versions of Python the outcome of an operation with NaN as
+ input depended on platform and libm implementation.
+
.. seealso::
Module :mod:`cmath`
Complex number versions of many of these functions.
-