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(python2.1-lib.info)math

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Mathematical functions
======================

Mathematical functions (`sin()' etc.).

This module is always available.  It provides access to the
mathematical functions defined by the C standard.

These functions cannot be used with complex numbers; use the functions
of the same name from the `cmath' module if you require support for
complex numbers.  The distinction between functions which support
complex numbers and those which don't is made since most users do not
want to learn quite as much mathematics as required to understand
complex numbers.  Receiving an exception instead of a complex result
allows earlier detection of the unexpected complex number used as a
parameter, so that the programmer can determine how and why it was
generated in the first place.

The following functions provided by this module:

`acos(x)'
     Return the arc cosine of X.

`asin(x)'
     Return the arc sine of X.

`atan(x)'
     Return the arc tangent of X.

`atan2(y, x)'
     Return `atan(Y / X)'.

`ceil(x)'
     Return the ceiling of X as a float.

`cos(x)'
     Return the cosine of X.

`cosh(x)'
     Return the hyperbolic cosine of X.

`exp(x)'
     Return `e**X'.

`fabs(x)'
     Return the absolute value of the floating point number X.

`floor(x)'
     Return the floor of X as a float.

`fmod(x, y)'
     Return `fmod(X, Y)', as defined by the platform C library.  Note
     that the Python expression `X % Y' may not return the same result.

`frexp(x)'
     Return the mantissa and exponent of X as the pair `(M, E)'.  M is
     a float and E is an integer such that `X == M * 2**E'.  If X is
     zero, returns `(0.0, 0)', otherwise `0.5 <= abs(M) < 1'.

`hypot(x, y)'
     Return the Euclidean distance, `sqrt(X*X + Y*Y)'.

`ldexp(x, i)'
     Return `X * (2**I)'.

`log(x)'
     Return the natural logarithm of X.

`log10(x)'
     Return the base-10 logarithm of X.

`modf(x)'
     Return the fractional and integer parts of X.  Both results carry
     the sign of X.  The integer part is returned as a float.

`pow(x, y)'
     Return `X**Y'.

`sin(x)'
     Return the sine of X.

`sinh(x)'
     Return the hyperbolic sine of X.

`sqrt(x)'
     Return the square root of X.

`tan(x)'
     Return the tangent of X.

`tanh(x)'
     Return the hyperbolic tangent of X.

Note that `frexp()' and `modf()' have a different call/return pattern
than their C equivalents: they take a single argument and return a pair
of values, rather than returning their second return value through an
`output parameter' (there is no such thing in Python).

The module also defines two mathematical constants:

`pi'
     The mathematical constant _pi_.

`e'
     The mathematical constant _e_.

See also:
     Note: cmath Complex number versions of many of these functions.