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(python2.1-lib.info)whrandom

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Pseudo-random number generator
==============================

Floating point pseudo-random number generator.

_This is deprecated in Python 2.1.  Use `random' instead._

*Note:*  This module was an implementation detail of the `random'
module in releases of Python prior to 2.1.  It is no longer used.
Please do not use this module directly; use `random' instead.

This module implements a Wichmann-Hill pseudo-random number generator
class that is also named `whrandom'.  Instances of the `whrandom' class
conform to the Random Number Generator interface described in section .
They also offer the following method, specific to the Wichmann-Hill
algorithm:

`seed([x, y, z])'
     Initializes the random number generator from the integers X, Y and
     Z.  When the module is first imported, the random number is
     initialized using values derived from the current time.  If X, Y,
     and Z are either omitted or `0', the seed will be computed from
     the current system time.  If one or two of the parameters are `0',
     but not all three, the zero values are replaced by ones.  This
     causes some apparently different seeds to be equal, with the
     corresponding result on the pseudo-random series produced by the
     generator.

`choice(seq)'
     Chooses a random element from the non-empty sequence SEQ and
     returns it.

`randint(a, b)'
     Returns a random integer N such that `A<=N<=B'.

`random()'
     Returns the next random floating point number in the range [0.0
     ... 1.0).

`seed(x, y, z)'
     Initializes the random number generator from the integers X, Y and
     Z.  When the module is first imported, the random number is
     initialized using values derived from the current time.

`uniform(a, b)'
     Returns a random real number N such that `A<=N<B'.

When imported, the `whrandom' module also creates an instance of the
`whrandom' class, and makes the methods of that instance available at
the module level.  Therefore one can write either `N =
whrandom.random()' or:

     generator = whrandom.whrandom()
     N = generator.random()

Note that using separate instances of the generator leads to
independent sequences of pseudo-random numbers.

See also:
     Note: random Generators for various random distributions and
     documentation for the Random Number Generator interface.
     Wichmann, B. A. & Hill, I. D., "Algorithm AS 183:  An efficient
     and portable pseudo-random number generator",  31 (1982) 188-190.