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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.
| KRandomSequence ( long lngSeed = 0 )
| KRandomSequence |
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 kapp->random() instead.
Parameters:
| lngSeed | Seed to initialize the sequence with. If lngSeed is 0, the sequence is initialized with a value from KApplication::random(). |
| ~KRandomSequence ()
| ~KRandomSequence |
[virtual]
Standard destructor
| KRandomSequence (const KRandomSequence &a)
| KRandomSequence |
Copy constructor
| KRandomSequence & operator= (const KRandomSequence &a)
| operator= |
Assignment
| void setSeed ( long lngSeed = 1 )
| setSeed |
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 KApplication::random(). |
| double getDouble ()
| getDouble |
Get the next number from the pseudo-random sequence.
Returns: a psuedo-random double value between [0,1[
| unsigned long getLong (unsigned long max)
| getLong |
Get the next number from the pseudo-random sequence.
Returns: a pseudo-random integer value between [0, max[ with 0 <= max < 1.000.000
| bool getBool ()
| getBool |
Get a boolean from the pseudo-random sequence.
Returns: a boolean which is either true or false
| void randomize (QGList *list)
| randomize |
Put a list in random order.
Parameters:
| list | the list whose order will be modified |
| void modulate (int i)
| modulate |
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 usefull 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 favourable response or to predict the response for a certain move based on the response to another move.
Parameters:
| i | the sequence identified |