KRandomSequence

KRandomSequence Class Reference

#include <KRandomSequence>

Public Member Functions

 KRandomSequence (int intSeed=0)
 
 KRandomSequence (long lngSeed)
 
 KRandomSequence (const KRandomSequence &a)
 
virtual ~KRandomSequence ()
 
bool getBool ()
 
double getDouble ()
 
unsigned int getInt (unsigned int max)
 
unsigned long getLong (unsigned long max)
 
void modulate (int i)
 
KRandomSequenceoperator= (const KRandomSequence &a)
 
template<typename T >
void randomize (QList< T > &list)
 
void setSeed (int intSeed=0)
 
void setSeed (long lngSeed=0)
 

Detailed Description

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 [email protected][email protected]tro.[email protected]keele[email protected].ac.[email protected]uk

Definition at line 31 of file krandomsequence.h.

Constructor & Destructor Documentation

KRandomSequence::KRandomSequence ( int  intSeed = 0)
explicit

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

Do not use methods working with long type because on 64-bit their size is different.

Definition at line 35 of file krandomsequence.cpp.

KRandomSequence::~KRandomSequence ( )
virtual

Standard destructor.

Definition at line 41 of file krandomsequence.cpp.

KRandomSequence::KRandomSequence ( const KRandomSequence a)

Copy constructor.

Definition at line 46 of file krandomsequence.cpp.

Member Function Documentation

bool KRandomSequence::getBool ( )

Get a boolean from the pseudo-random sequence.

Returns
a boolean which is either true or false

Definition at line 200 of file krandomsequence.cpp.

double KRandomSequence::getDouble ( )

Get the next number from the pseudo-random sequence.

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

Definition at line 169 of file krandomsequence.cpp.

unsigned int KRandomSequence::getInt ( unsigned int  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

Definition at line 192 of file krandomsequence.cpp.

void KRandomSequence::modulate ( 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
ithe sequence identified

Definition at line 154 of file krandomsequence.cpp.

KRandomSequence & KRandomSequence::operator= ( const KRandomSequence a)

Assignment.

Definition at line 51 of file krandomsequence.cpp.

template<typename T >
void KRandomSequence::randomize ( QList< T > &  list)
inline

Put a list in random order.

Since kdelibs 4.11, this function uses a more efficient algorithm (Fisher-Yates). Therefore, the order of the items in the randomized list is different from the one in earlier versions if the same seed value is used for the random sequence.

Parameters
listthe list whose order will be modified
Note
modifies the list in place

Definition at line 112 of file krandomsequence.h.

void KRandomSequence::setSeed ( int  intSeed = 0)

Restart the sequence based on lngSeed.

Parameters
intSeedSeed to initialize the sequence with. If lngSeed is 0, the sequence is initialized with a value from KRandom::random().

Definition at line 67 of file krandomsequence.cpp.


The documentation for this class was generated from the following files:
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