diff -r ffa851df0825 -r 2fb8b9db1c86 symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/cmath.rst
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/cmath.rst	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,250 @@
+
+:mod:`cmath` --- Mathematical functions for complex numbers
+===========================================================
+
+.. module:: cmath
+   :synopsis: Mathematical functions for complex numbers.
+
+
+This module is always available.  It provides access to mathematical functions
+for complex numbers.  The functions in this module accept integers,
+floating-point numbers or complex numbers as arguments. They will also accept
+any Python object that has either a :meth:`__complex__` or a :meth:`__float__`
+method: these methods are used to convert the object to a complex or
+floating-point number, respectively, and the function is then applied to the
+result of the conversion.
+
+.. note::
+
+   On platforms with hardware and system-level support for signed
+   zeros, functions involving branch cuts are continuous on *both*
+   sides of the branch cut: the sign of the zero distinguishes one
+   side of the branch cut from the other.  On platforms that do not
+   support signed zeros the continuity is as specified below.
+
+
+Complex coordinates
+-------------------
+
+Complex numbers can be expressed by two important coordinate systems.
+Python's :class:`complex` type uses rectangular coordinates where a number
+on the complex plain is defined by two floats, the real part and the imaginary
+part.
+
+Definition::
+
+   z = x + 1j * y
+
+   x := real(z)
+   y := imag(z)
+
+In engineering the polar coordinate system is popular for complex numbers. In
+polar coordinates a complex number is defined by the radius *r* and the phase
+angle *phi*. The radius *r* is the absolute value of the complex, which can be
+viewed as distance from (0, 0). The radius *r* is always 0 or a positive float.
+The phase angle *phi* is the counter clockwise angle from the positive x axis,
+e.g. *1* has the angle *0*, *1j* has the angle *π/2* and *-1* the angle *-π*.
+
+.. note::
+   While :func:`phase` and func:`polar` return *+π* for a negative real they
+   may return *-π* for a complex with a very small negative imaginary
+   part, e.g. *-1-1E-300j*.
+
+
+Definition::
+
+   z = r * exp(1j * phi)
+   z = r * cis(phi)
+
+   r := abs(z) := sqrt(real(z)**2 + imag(z)**2)
+   phi := phase(z) := atan2(imag(z), real(z))
+   cis(phi) := cos(phi) + 1j * sin(phi)
+
+
+.. function:: phase(x)
+
+   Return phase, also known as the argument, of a complex.
+
+   .. versionadded:: 2.6
+
+
+.. function:: polar(x)
+
+   Convert a :class:`complex` from rectangular coordinates to polar 
+   coordinates. The function returns a tuple with the two elements
+   *r* and *phi*. *r* is the distance from 0 and *phi* the phase 
+   angle.
+
+   .. versionadded:: 2.6
+
+
+.. function:: rect(r, phi)
+
+   Convert from polar coordinates to rectangular coordinates and return
+   a :class:`complex`.
+
+   .. versionadded:: 2.6
+
+
+
+cmath functions
+---------------
+
+.. function:: acos(x)
+
+   Return the arc cosine of *x*. There are two branch cuts: One extends right from
+   1 along the real axis to ∞, continuous from below. The other extends left from
+   -1 along the real axis to -∞, continuous from above.
+
+
+.. function:: acosh(x)
+
+   Return the hyperbolic arc cosine of *x*. There is one branch cut, extending left
+   from 1 along the real axis to -∞, continuous from above.
+
+
+.. function:: asin(x)
+
+   Return the arc sine of *x*. This has the same branch cuts as :func:`acos`.
+
+
+.. function:: asinh(x)
+
+   Return the hyperbolic arc sine of *x*. There are two branch cuts:
+   One extends from ``1j`` along the imaginary axis to ``∞j``,
+   continuous from the right.  The other extends from ``-1j`` along
+   the imaginary axis to ``-∞j``, continuous from the left.
+
+   .. versionchanged:: 2.6
+      branch cuts moved to match those recommended by the C99 standard
+
+
+.. function:: atan(x)
+
+   Return the arc tangent of *x*. There are two branch cuts: One extends from
+   ``1j`` along the imaginary axis to ``∞j``, continuous from the right. The
+   other extends from ``-1j`` along the imaginary axis to ``-∞j``, continuous
+   from the left.
+
+   .. versionchanged:: 2.6
+      direction of continuity of upper cut reversed
+
+
+.. function:: atanh(x)
+
+   Return the hyperbolic arc tangent of *x*. There are two branch cuts: One
+   extends from ``1`` along the real axis to ``∞``, continuous from below. The
+   other extends from ``-1`` along the real axis to ``-∞``, continuous from
+   above.
+
+   .. versionchanged:: 2.6
+      direction of continuity of right cut reversed
+
+
+.. function:: cos(x)
+
+   Return the cosine of *x*.
+
+
+.. function:: cosh(x)
+
+   Return the hyperbolic cosine of *x*.
+
+
+.. function:: exp(x)
+
+   Return the exponential value ``e**x``.
+
+
+.. function:: isinf(x)
+
+   Return *True* if the real or the imaginary part of x is positive
+   or negative infinity.
+
+   .. versionadded:: 2.6
+
+
+.. function:: isnan(x)
+
+   Return *True* if the real or imaginary part of x is not a number (NaN).
+
+   .. versionadded:: 2.6
+
+
+.. function:: log(x[, base])
+
+   Returns the logarithm of *x* to the given *base*. If the *base* is not
+   specified, returns the natural logarithm of *x*. There is one branch cut, from 0
+   along the negative real axis to -∞, continuous from above.
+
+   .. versionchanged:: 2.4
+      *base* argument added.
+
+
+.. function:: log10(x)
+
+   Return the base-10 logarithm of *x*. This has the same branch cut as
+   :func:`log`.
+
+
+.. function:: sin(x)
+
+   Return the sine of *x*.
+
+
+.. function:: sinh(x)
+
+   Return the hyperbolic sine of *x*.
+
+
+.. function:: sqrt(x)
+
+   Return the square root of *x*. This has the same branch cut as :func:`log`.
+
+
+.. function:: tan(x)
+
+   Return the tangent of *x*.
+
+
+.. function:: tanh(x)
+
+   Return the hyperbolic tangent of *x*.
+
+The module also defines two mathematical constants:
+
+
+.. data:: pi
+
+   The mathematical constant *pi*, as a float.
+
+
+.. data:: e
+
+   The mathematical constant *e*, as a float.
+
+.. index:: module: math
+
+Note that the selection of functions is similar, but not identical, to that in
+module :mod:`math`.  The reason for having two modules is that some users aren't
+interested in complex numbers, and perhaps don't even know what they are.  They
+would rather have ``math.sqrt(-1)`` raise an exception than return a complex
+number. Also note that the functions defined in :mod:`cmath` always return a
+complex number, even if the answer can be expressed as a real number (in which
+case the complex number has an imaginary part of zero).
+
+A note on branch cuts: They are curves along which the given function fails to
+be continuous.  They are a necessary feature of many complex functions.  It is
+assumed that if you need to compute with complex functions, you will understand
+about branch cuts.  Consult almost any (not too elementary) book on complex
+variables for enlightenment.  For information of the proper choice of branch
+cuts for numerical purposes, a good reference should be the following:
+
+
+.. seealso::
+
+   Kahan, W:  Branch cuts for complex elementary functions; or, Much ado about
+   nothing's sign bit.  In Iserles, A., and Powell, M. (eds.), The state of the art
+   in numerical analysis. Clarendon Press (1987) pp165-211.
+
+