Doc/libmath.tex

   1 \section{Built-in Module \module{math}}
   2 \label{module-math}
   3
   4 \bimodindex{math}
   5 This module is always available.
   6 It provides access to the mathematical functions defined by the \C{}
   7 standard.
   8 They are:
   9
  10 \begin{funcdesc}{acos}{x}
  11 Return the arc cosine of \var{x}.
  12 \end{funcdesc}
  13
  14 \begin{funcdesc}{asin}{x}
  15 Return the arc sine of \var{x}.
  16 \end{funcdesc}
  17
  18 \begin{funcdesc}{atan}{x}
  19 Return the arc tangent of \var{x}.
  20 \end{funcdesc}
  21
  22 \begin{funcdesc}{atan2}{x, y}
  23 Return \code{atan(\var{x} / \var{y})}.
  24 \end{funcdesc}
  25
  26 \begin{funcdesc}{ceil}{x}
  27 Return the ceiling of \var{x} as a real.
  28 \end{funcdesc}
  29
  30 \begin{funcdesc}{cos}{x}
  31 Return the cosine of \var{x}.
  32 \end{funcdesc}
  33
  34 \begin{funcdesc}{cosh}{x}
  35 Return the hyperbolic cosine of \var{x}.
  36 \end{funcdesc}
  37
  38 \begin{funcdesc}{exp}{x}
  39 Return \code{e**\var{x}}.
  40 \end{funcdesc}
  41
  42 \begin{funcdesc}{fabs}{x}
  43 Return the absolute value of the real \var{x}.
  44 \end{funcdesc}
  45
  46 \begin{funcdesc}{floor}{x}
  47 Return the floor of \var{x} as a real.
  48 \end{funcdesc}
  49
  50 \begin{funcdesc}{fmod}{x, y}
  51 Return \code{\var{x} \%\ \var{y}}.
  52 \end{funcdesc}
  53
  54 \begin{funcdesc}{frexp}{x}
  55 Return the matissa and exponent for \var{x}.  The mantissa is
  56 positive.
  57 \end{funcdesc}
  58
  59 \begin{funcdesc}{hypot}{x, y}
  60 Return the Euclidean distance, \code{sqrt(\var{x}*\var{x} + \var{y}*\var{y})}.
  61 \end{funcdesc}
  62
  63 \begin{funcdesc}{ldexp}{x, i}
  64 Return \code{\var{x} * (2**\var{i})}.
  65 \end{funcdesc}
  66
  67 \begin{funcdesc}{log}{x}
  68 Return the natural logarithm of \var{x}.
  69 \end{funcdesc}
  70
  71 \begin{funcdesc}{log10}{x}
  72 Return the base-10 logarithm of \var{x}.
  73 \end{funcdesc}
  74
  75 \begin{funcdesc}{modf}{x}
  76 Return the fractional and integer parts of \var{x}.  Both results
  77 carry the sign of \var{x}.  The integer part is returned as a real.
  78 \end{funcdesc}
  79
  80 \begin{funcdesc}{pow}{x, y}
  81 Return \code{\var{x}**\var{y}}.
  82 \end{funcdesc}
  83
  84 \begin{funcdesc}{sin}{x}
  85 Return the sine of \var{x}.
  86 \end{funcdesc}
  87
  88 \begin{funcdesc}{sinh}{x}
  89 Return the hyperbolic sine of \var{x}.
  90 \end{funcdesc}
  91
  92 \begin{funcdesc}{sqrt}{x}
  93 Return the square root of \var{x}.
  94 \end{funcdesc}
  95
  96 \begin{funcdesc}{tan}{x}
  97 Return the tangent of \var{x}.
  98 \end{funcdesc}
  99
 100 \begin{funcdesc}{tanh}{x}
 101 Return the hyperbolic tangent of \var{x}.
 102 \end{funcdesc}
 103
 104 Note that \function{frexp()} and \function{modf()} have a different
 105 call/return pattern than their \C{} equivalents: they take a single
 106 argument and return a pair of values, rather than returning their
 107 second return value through an `output parameter' (there is no such
 108 thing in Python).
 109
 110 The module also defines two mathematical constants:
 111
 112 \begin{datadesc}{pi}
 113 The mathematical constant \emph{pi}.
 114 \end{datadesc}
 115
 116 \begin{datadesc}{e}
 117 The mathematical constant \emph{e}.
 118 \end{datadesc}
 119
 120 \begin{seealso}
 121   \seemodule{cmath}{Complex number versions of many of these functions.}
 122 \end{seealso}