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Random\Engine\PcgOneseq128XslRr64::jump

(PHP 8 >= 8.2.0)

Random\Engine\PcgOneseq128XslRr64::jumpEfficiently move the engine ahead multiple steps

Beschreibung

public Random\Engine\PcgOneseq128XslRr64::jump(int $advance): void

Moves the algorithm’s state ahead by the number of steps given by advance, as if Random\Engine\PcgOneseq128XslRr64::generate() was called that many times.

Parameter-Liste

advance

The number of steps to move ahead; must be 0 or greater.

Rückgabewerte

Es wird kein Wert zurückgegeben.

Fehler/Exceptions

  • If advance is less than 0, a ValueError will be thrown.

Beispiele

Beispiel #1 Random\Engine\PcgOneseq128XslRr64::jump() example

<?php
$a
= new \Random\Engine\PcgOneseq128XslRr64(0);
$b = clone $a;

for (
$i = 0; $i < 1_000; $i++) {
$a->generate();
}
$b->jump(1_000);

echo
"A: ", bin2hex( $a->generate() ), "\n";
echo
"B: ", bin2hex( $b->generate() ), "\n";
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

A: e6d0d5813913a424
B: e6d0d5813913a424

Beispiel #2 Randomizer methods may call the engine more than once

<?php
$a
= new \Random\Randomizer(new \Random\Engine\PcgOneseq128XslRr64(42659));
$b = new \Random\Randomizer(clone $a->engine);

$a->getInt(1, 1572864); // Performs two calls to generate().
$a->getInt(1, 1572864);

$b->engine->jump(2);

// Because the first call to ->getInt() called ->generate() twice
// the engines do not match up after performing a ->jump(2).
echo "A: ", bin2hex( $a->engine->generate() ), "\n";
echo
"B: ", bin2hex( $b->engine->generate() ), "\n";

// Now the B engine matches the A engine.
echo "B: ", bin2hex( $b->engine->generate() ), "\n";
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

A: 1e9f3107d56653d0
B: a156c0086dd79d44
B: 1e9f3107d56653d0
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