Pseudo-random numbers/PCG32: Difference between revisions
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Line 591:
3 : 19809
4 : 20005</pre>
=={{header|Dart}}==
{{trans|Python}}
<syntaxhighlight lang="Dart">
import 'dart:math';
class PCG32 {
BigInt fState = BigInt.zero;
BigInt fInc = BigInt.zero;
final BigInt mask64 = (BigInt.one << 64) - BigInt.one;
final BigInt mask32 = (BigInt.one << 32) - BigInt.one;
final BigInt k = BigInt.parse('6364136223846793005');
PCG32(BigInt seedState, BigInt seedSequence) {
seed(seedState, seedSequence);
}
PCG32.noSeed() {
fState = BigInt.zero;
fInc = BigInt.zero;
}
void seed(BigInt seedState, BigInt seedSequence) {
fState = BigInt.zero;
fInc = ((seedSequence << 1) | BigInt.one) & mask64;
nextInt();
fState += seedState;
nextInt();
}
BigInt nextInt() {
BigInt old = fState;
fState = ((old * k) + fInc) & mask64;
BigInt xorshifted = ( ((old >> 18) ^ old) >> 27) & mask32;
BigInt rot = (old >> 59) & mask32;
BigInt shifted = (xorshifted >> rot.toInt()) | (xorshifted << ((-rot) & BigInt.from(31)).toInt());
return shifted & mask32;
}
double nextFloat() {
return nextInt().toDouble() / (BigInt.one << 32).toDouble();
}
List<BigInt> nextIntRange(int size) {
List<BigInt> result = [];
for (int i = 0; i < size; i++) {
result.add(nextInt());
}
return result;
}
}
void main() {
var pcg32 = PCG32(BigInt.from(42), BigInt.from(54));
for (int i = 0; i < 5; i++) {
print(pcg32.nextInt().toString());
}
pcg32.seed(BigInt.from(987654321), BigInt.one);
var count = <int, int>{};
for (int i = 0; i < 100000; i++) {
int key = (pcg32.nextFloat() * 5).truncate();
count[key] = (count[key] ?? 0) + 1;
}
print('\nThe counts for 100,000 repetitions are:');
count.forEach((key, value) {
print('$key : $value');
});
}
</syntaxhighlight>
{{out}}
<pre>
2707161783
2068313097
3122475824
2211639955
3215226955
The counts for 100,000 repetitions are:
2 : 20115
3 : 19809
0 : 20049
4 : 20005
1 : 20022
</pre>
=={{header|Delphi}}==
Line 2,564 ⟶ 2,654:
{{libheader|Wren-big}}
As Wren doesn't have a 64-bit integer type, we use BigInt instead.
<syntaxhighlight lang="
var Const = BigInt.new("6364136223846793005")
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