| \section{Built-in Module \sectcode{cmath}} |
| \label{module-cmath} |
| |
| \bimodindex{cmath} |
| \renewcommand{\indexsubitem}{(in module cmath)} |
| 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}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{acosh}{x} |
| Return the hyperbolic arc cosine of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{asin}{x} |
| Return the arc sine of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{asinh}{x} |
| Return the hyperbolic arc sine of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{atan}{x} |
| Return the arc tangent of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{atanh}{x} |
| Return the hyperbolic arc tangent of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{cos}{x} |
| Return the cosine of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{cosh}{x} |
| Return the hyperbolic cosine of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{exp}{x} |
| Return the exponential value $\mbox{e}^x$. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{log}{x} |
| Return the natural logarithm of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{log10}{x} |
| Return the base-10 logarithm of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{sin}{x} |
| Return the sine of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{sinh}{x} |
| Return the hyperbolic sine of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{sqrt}{x} |
| Return the square root of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{tan}{x} |
| Return the tangent of \var{x}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{tanh}{x} |
| Return the hyperbolic tangent of \var{x}. |
| \end{funcdesc} |
| |
| The module also defines two mathematical constants: |
| |
| \begin{datadesc}{pi} |
| The mathematical constant \emph{pi}, as a real. |
| \end{datadesc} |
| |
| \begin{datadesc}{e} |
| The mathematical constant \emph{e}, as a real. |
| \end{datadesc} |
| |
| Note that the selection of functions is similar, but not identical, to |
| that in module \code{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 \code{math.sqrt(-1)} |
| raise an exception than return a complex number. Also note that the |
| functions defined in \code{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). |