source: trunk/essentials/dev-lang/python/Doc/lib/libcmath.tex@ 3368

\section{\module{cmath} ---
         Mathematical functions for complex numbers}

\declaremodule{builtin}{cmath}
\modulesynopsis{Mathematical functions for complex numbers.}

This module is always available.  It provides access to mathematical
functions for complex numbers.  The functions are:

\begin{funcdesc}{acos}{x}
Return the arc cosine of \var{x}.
There are two branch cuts:
One extends right from 1 along the real axis to \infinity, continuous
from below.
The other extends left from -1 along the real axis to -\infinity,
continuous from above.
\end{funcdesc}

\begin{funcdesc}{acosh}{x}
Return the hyperbolic arc cosine of \var{x}.
There is one branch cut, extending left from 1 along the real axis
to -\infinity, continuous from above.
\end{funcdesc}

\begin{funcdesc}{asin}{x}
Return the arc sine of \var{x}.
This has the same branch cuts as \function{acos()}.
\end{funcdesc}

\begin{funcdesc}{asinh}{x}
Return the hyperbolic arc sine of \var{x}.
There are two branch cuts, extending left from \plusminus\code{1j} to
\plusminus-\infinity\code{j}, both continuous from above.
These branch cuts should be considered a bug to be corrected in a
future release.
The correct branch cuts should extend along the imaginary axis,
one from \code{1j} up to \infinity\code{j} and continuous from the
right, and one from -\code{1j} down to -\infinity\code{j} and
continuous from the left.
\end{funcdesc}

\begin{funcdesc}{atan}{x}
Return the arc tangent of \var{x}.
There are two branch cuts: