KRandomSequence

KDE 4.2 PyKDE API Reference

- KDE's Python API

# KRandomSequence Class Reference

`from PyKDE4.kdecore import *`

## Detailed Description

\class KRandomSequence krandomsequence.h <KRandomSequence>

A class to create a pseudo-random sequence

Given a seed number, this class will produce a sequence of pseudo-random numbers. This would typically be used in applications like games.

In general, you should instantiate a KRandomSequence object and pass along your seed number in the constructor. From then on, simply call getDouble or getLong to obtain the next number in the sequence.

Author:
  Sean Harmer <sh@astro.keele.ac.uk>

## Methods
| __init__ (self, long lngSeed=0)
| __init__ (self, KRandomSequence a)
bool | getBool (self)
float | getDouble (self)
long | getLong (self, long max)
| modulate (self, int i)
| setSeed (self, long lngSeed=0)

## Method Documentation

__init__ | ( | self, |
|  | long | lngSeed=0
| ) |  |  |

Creates a pseudo-random sequence based on the seed lngSeed.

A Pseudo-random sequence is different for each seed but can be reproduced by starting the sequence with the same seed.

If you need a single value which needs to be unpredictable, you need to use KRandom.random() instead.

Parameters:

  | lngSeed | Seed to initialize the sequence with. If lngSeed is 0, the sequence is initialized with a value from KRandom.random().

__init__ | ( | self, |
|  | KRandomSequence | a
| ) |  |  |

Copy constructor

bool getBool | ( |  | self ) |

Get a boolean from the pseudo-random sequence.

Returns:
  a boolean which is either true or false

float getDouble | ( |  | self ) |

Get the next number from the pseudo-random sequence.

Returns:
  a pseudo-random double value between [0,1)

long getLong | ( | self, |
|  | long | max
| ) |  |  |

Get the next number from the pseudo-random sequence.

Returns:
  a pseudo-random integer value between [0, max) with 0 <= max < 1.000.000

modulate | ( | self, |
|  | int | i
| ) |  |  |

Modulate the random sequence.

If S(i) is the sequence of numbers that will follow given the current state after calling modulate(i), then S(i) != S(j) for i != j and S(i) == S(j) for i == j.

This can be useful in game situation where "undo" restores the state of the random sequence. If the game modulates the random sequence with the move chosen by the player, the random sequence will be identical whenever the player "redo"-s his or hers original move, but different when the player chooses another move.

With this scenario "undo" can no longer be used to repeat a certain move over and over again until the computer reacts with a favorable response or to predict the response for a certain move based on the response to another move.

Parameters:

  | i | the sequence identified

setSeed | ( | self, |
|  | long | lngSeed=0
| ) |  |  |

Restart the sequence based on lngSeed.

Parameters:

  | lngSeed | Seed to initialize the sequence with. If lngSeed is 0, the sequence is initialized with a value from KRandom.random().