Pseudo-random numbers/Splitmix64: Difference between revisions
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{{
Splitmix64 is the default pseudo-random number generator algorithm in Java and is included / available in many other languages. It uses a fairly simple algorithm that, though it is considered to be poor for cryptographic purposes, is very fast to calculate, and is "good enough" for many random number needs. It passes several fairly rigorous PRNG "fitness" tests that some more complex algorithms fail.
Line 62:
=={{header|11l}}==
{{trans|Python}}
<syntaxhighlight lang="11l">T Splitmix64
UInt64 state
F seed(seed_state)
.state = seed_state
F next_int()
.state += 9E37'79B9'7F4A'7C15
V z = .state
z = (z (+) (z >> 30)) * BF58'476D'1CE4'E5B9
z = (z (+) (z >> 27)) * 94D0'49BB'1331'11EB
R z (+) (z >> 31)
F next_float()
R Float(.next_int()) / 2.0^64
V random_gen = Splitmix64()
random_gen.seed(1234567)
L 5
print(random_gen.next_int())
random_gen.seed(987654321)
V hist = Dict(0.<5, i -> (i, 0))
L 100'000
hist[Int(random_gen.next_float() * 5)]++
print(hist)</syntaxhighlight>
{{out}}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
[0 = 20027, 1 = 19892, 2 = 20073, 3 = 19978, 4 = 20030]
</pre>
=={{header|Ada}}==
The random number functions are written in a stand-alone package. The package is split into a package specification defining the interfaces to the public subprograms and a body containing the implementation of the random number generator.
'''package specification:'''
<syntaxhighlight lang="ada">with Interfaces; use Interfaces;
package Random_Splitmix64 is
function next_Int return Unsigned_64;
function next_float return Float;
procedure Set_State (Seed : in Unsigned_64);
end Random_Splitmix64;</syntaxhighlight>
'''package body:'''
<syntaxhighlight lang="ada">package body Random_Splitmix64 is
Internal : Unsigned_64 := 1234567;
--------------
-- next_Int --
--------------
function next_Int return Unsigned_64 is
Z : Unsigned_64;
begin
Internal := Internal + 16#9e3779b97f4a7c15#;
Z := Internal;
Z := (Z xor Shift_Right(Z, 30)) * 16#bf58476d1ce4e5b9#;
Z := (Z xor Shift_Right(Z, 27)) * 16#94d049bb133111eb#;
return Z xor Shift_Right(Z, 31);
end next_Int;
----------------
-- next_float --
----------------
function next_float return Float is
begin
return float(next_int) / (2.0 ** 64);
end next_float;
---------------
-- Set_State --
---------------
procedure Set_State (Seed : in Unsigned_64) is
begin
Internal := Seed;
end Set_State;
end Random_Splitmix64;</syntaxhighlight>
'''Main procedure:'''
<syntaxhighlight lang="ada">with Interfaces; use Interfaces;
with Random_Splitmix64; use Random_Splitmix64;
with Ada.Text_IO; use Ada.Text_IO;
procedure Main is
subtype idx is Integer range 0 .. 4;
type answer_arr is array (idx) of Natural;
Vec : answer_arr := (others => 0);
J : Integer;
fj : Float;
begin
Set_State (1_234_567);
for I in 1 .. 5 loop
Put (Unsigned_64'Image (next_Int));
New_Line;
end loop;
Set_State (987_654_321);
for I in 1 .. 100_000 loop
fj := Float'Truncation (next_float * 5.0);
J := Integer (fj);
Vec (J) := Vec (J) + 1;
end loop;
for I in Vec'Range loop
Put_Line (I'Image & ":" & Integer'Image (Vec (I)));
end loop;
end Main;
</syntaxhighlight>
{{out}}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
0: 20027
1: 19892
2: 20073
3: 19978
4: 20030
</pre>
=={{header|ALGOL 68}}==
{{works with|ALGOL 68G|Any Tested with release 2.8.3.win32}}
<
# note that although LONG INT is 64 bits in Algol 68G, LONG BITS is longer than 64 bits #
LONG BITS mask 64 = LONG 16rffffffffffffffff;
Line 112 ⟶ 247:
print( ( newline ) )
END
END</
{{out}}
<pre>
Line 125 ⟶ 260:
=={{header|C}}==
Code copied from the reference C implementation used by Java, and using GNU GCC v7.1.1.
<
To the extent possible under law, the author has dedicated all copyright
Line 171 ⟶ 306:
printf("%d: %d ", i, vec5[i]);
}
</
<pre>
6457827717110365317
Line 179 ⟶ 314:
16408922859458223821
0: 20027 1: 19892 2: 20073 3: 19978 4: 20030
</pre>
=={{header|C++}}==
<syntaxhighlight lang="c++">
#include <iostream>
#include <cmath>
#include <vector>
class Splitmix64 {
public:
Splitmix64() { state = 0; }
Splitmix64(const uint64_t seed) : state(seed) {}
void seed(const uint64_t seed) {
state = seed;
}
uint64_t next_int() {
uint64_t z = ( state += 0x9e3779b97f4a7c15 );
z = ( z ^ ( z >> 30 ) ) * 0xbf58476d1ce4e5b9;
z = ( z ^ ( z >> 27 ) ) * 0x94d049bb133111eb;
return z ^ ( z >> 31 );
}
double next_float() {
return next_int() / twoPower64;
}
private:
uint64_t state;
const double twoPower64 = pow(2.0, 64);
};
int main() {
Splitmix64 random;
random.seed(1234567);
for ( int32_t i = 0; i < 5; ++i ) {
std::cout << random.next_int() << std::endl;
}
std::cout << std::endl;
Splitmix64 rand(987654321);
std::vector<uint32_t> counts(5, 0);
for ( int32_t i = 0; i < 100'000; ++i ) {
uint32_t value = floor(rand.next_float() * 5.0);
counts[value] += 1;
}
for ( int32_t i = 0; i < 5; ++i ) {
std::cout << i << ": " << counts[i] << " ";
}
std::cout << std::endl;
}
</syntaxhighlight>
{{ out }}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
0: 20027 1: 19892 2: 20073 3: 19978 4: 20030
</pre>
=={{header|Factor}}==
<
math.statistics namespaces prettyprint sequences ;
Line 203 ⟶ 402:
"Seed: 987654321; first 100,000 float values histogram" print
987654321 seed 100,000 [ next-float 5 * >integer ] replicate
histogram .</
{{out}}
<pre>
Line 215 ⟶ 414:
Seed: 987654321; first 100,000 float values histogram
H{ { 0 20027 } { 1 19892 } { 2 20073 } { 3 19978 } { 4 20030 } }
</pre>
=={{header|Forth}}==
{{works with|gforth|0.7.3}}
<syntaxhighlight lang="forth">variable rnd-state
: rnd-base-op ( z factor shift -- u ) 2 pick swap rshift rot xor * ;
: rnd-next ( -- u )
$9e3779b97f4a7c15 rnd-state +!
rnd-state @
$bf58476d1ce4e5b9 #30 rnd-base-op
$94d049bb133111eb #27 rnd-base-op
#1 #31 rnd-base-op
;
#1234567 rnd-state !
cr
rnd-next u. cr
rnd-next u. cr
rnd-next u. cr
rnd-next u. cr
rnd-next u. cr
: rnd-next-float ( -- f )
rnd-next 0 d>f 0 1 d>f f/
;
create counts 0 , 0 , 0 , 0 , 0 ,
: counts-fill
#987654321 rnd-state !
100000 0 do
rnd-next-float 5.0e0 f* f>d drop cells counts + dup @ 1+ swap !
loop
;
: counts-disp
5 0 do
cr i . ': emit bl emit
counts i cells + @ .
loop cr
;
counts-fill counts-disp</syntaxhighlight>
{{out}}
<pre>6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
0 : 20027
1 : 19892
2 : 20073
3 : 19978
4 : 20030
ok</pre>
=={{header|F_Sharp|F#}}==
<syntaxhighlight lang="fsharp">// Pure F# Implementation of SplitMix64
let a: uint64 = 0x9e3779b97f4a7c15UL
let nextInt (state: uint64) =
let newstate = state + (0x9e3779b97f4a7c15UL)
let rand = newstate
let rand = (rand ^^^ (rand >>> 30)) * 0xbf58476d1ce4e5b9UL
let rand = (rand ^^^ (rand >>> 27)) * 0x94d049bb133111ebUL
let rand = rand ^^^ (rand >>> 31)
(rand, newstate)
let nextFloat (state: uint64) =
let (rand, newState) = nextInt state
let randf = (rand / (1UL <<< 64)) |> float
(randf, newState)
[<EntryPoint>]
let main argv =
let state = 1234567UL
let (first, state) = nextInt state
let (second, state) = nextInt state
let (third, state) = nextInt state
let (fourth, state) = nextInt state
let (fifth, state) = nextInt state
printfn "%i" first
printfn "%i" second
printfn "%i" third
printfn "%i" fourth
printfn "%i" fifth
0</syntaxhighlight>
{{out}}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
</pre>
=={{header|Go}}==
<
import (
Line 257 ⟶ 557:
fmt.Printf(" %d : %d\n", i, counts[i])
}
}</
{{out}}
Line 273 ⟶ 573:
3 : 19978
4 : 20030
</pre>
=={{header|Haskell}}==
<syntaxhighlight lang="haskell">import Data.Bits
import Data.Word
import Data.List
next :: Word64 -> (Word64, Word64)
next state = f4 $ state + 0x9e3779b97f4a7c15
where
f1 z = (z `xor` (z `shiftR` 30)) * 0xbf58476d1ce4e5b9
f2 z = (z `xor` (z `shiftR` 27)) * 0x94d049bb133111eb
f3 z = z `xor` (z `shiftR` 31)
f4 s = ((f3 . f2 . f1) s, s)
randoms = unfoldr (pure . next)
toFloat n = fromIntegral n / (2^64 - 1)</syntaxhighlight>
<pre>λ> mapM_ print $ take 5 $ randoms 1234567
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
λ> let hist = map length . group . sort
λ> hist . take 100000 $ (floor . (*5) . toFloat) <$> (randoms 987654321)
[20027,19892,20073,19978,20030]</pre>
=={{header|Java}}==
Java integers are signed and so have a maximum value of 2^63 - 1, requiring the use of the BigInteger class for this task.
<syntaxhighlight lang="java">
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.MathContext;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public final class PseudoRandomSplitmix64 {
public static void main(String[] aArgs) {
Splitmix64 random = new Splitmix64();
random.seed(1234567);
for ( int i = 0; i < 5; i++ ) {
System.out.println(random.nextInt());
}
List<Integer> counts = new ArrayList<Integer>(Collections.nCopies(5, 0));
Splitmix64 rand = new Splitmix64(987654321);
for ( int i = 0; i < 100_000; i++ ) {
BigDecimal value = rand.nextFloat();
final int count = value.multiply(BigDecimal.valueOf(5.0)).toBigInteger().intValue();
counts.set(count, counts.get(count) + 1);
}
System.out.println(System.lineSeparator() + "The counts for 100,000 repetitions are: ");
for ( int i = 0; i < 5; i++ ) {
System.out.print(i + ": " + counts.get(i) + " ");
}
System.out.println();
}
}
final class Splitmix64 {
public Splitmix64() {
state = BigInteger.ZERO;
}
public Splitmix64(long aSeed) {
state = BigInteger.valueOf(aSeed).and(mask64);
}
public void seed(long aNumber) {
state = BigInteger.valueOf(aNumber);
}
public BigInteger nextInt() {
state = state.add(constant1).and(mask64);
BigInteger z = state;
z = z.xor(z.shiftRight(30)).multiply(constant2).and(mask64);
z = z.xor(z.shiftRight(27)).multiply(constant3).and(mask64);
BigInteger result = z.xor(z.shiftRight(31)).and(mask64);
return result;
}
public BigDecimal nextFloat() {
return new BigDecimal(nextInt()).divide(twoPower64, MathContext.DECIMAL64);
}
private BigInteger state;
private final BigInteger constant1 = new BigInteger("9e3779b97f4a7c15", 16);
private final BigInteger constant2 = new BigInteger("bf58476d1ce4e5b9", 16);
private final BigInteger constant3 = new BigInteger("94d049bb133111eb", 16);
private final BigInteger mask64 = BigInteger.ONE.shiftLeft(64).subtract(BigInteger.ONE);
private final BigDecimal twoPower64 = new BigDecimal(BigInteger.ONE.shiftLeft(64));
}
</syntaxhighlight>
{{ out }}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
The counts for 100,000 repetitions are:
0: 20027 1: 19892 2: 20073 3: 19978 4: 20030
</pre>
=={{header|Jasmin}}==
<syntaxhighlight lang="text">u64 c1 = 0x9e3779b97f4a7c15;
u64 c2 = 0xbf58476d1ce4e5b9;
u64 c3 = 0x94d049bb133111eb;
inline
fn next_int(reg u64 state) -> reg u64 {
reg u64 z a;
z = [state];
z += c1;
[state] = z;
a = z;
a >>= 30;
z ^= a;
z *= c2;
a = z;
a >>= 27;
z ^= a;
z *= c3;
a = z;
a >>= 31;
z ^= a;
return z;
}
inline
fn test() -> reg u64[5] {
reg u64 seed;
seed = 0x1000;
[seed] = 1234567;
inline int i;
reg u64[5] result;
for i = 0 to 5 {
result[i] = next_int(seed);
}
return result;
}
exec test(0x1000:8)</syntaxhighlight>
=={{header|jq}}==
'''Works with gojq, the Go implementation of jq'''
'''Adapted from [[#Wren|Wren]]'''
This entry assumes sufficiently precise integer arithmetic, e.g. as provided by gojq,
which supports infinite-precision integer arithmetic.
Unfortunately, though, gojq does not support efficient bitwise operations, and using
the following to generate 100,000 random numbers takes about 13 minutes on a 3GHz machine.
The main significance of this entry is thus to increase confidence in the correctness of the
definitions as well as in the Go implementation of jq.
In the following, a 'bitarray' is a 0/1 array, and when integers are represented by bitarrays, the first bit is the least-significant one. Unless otherwise indicated, the bitwise operations work on bitarrays.
'''Generic utilities'''
<syntaxhighlight lang="jq">
# Input: a string in base $b (2 to 35 inclusive)
# Output: a JSON number, being the decimal value corresponding to the input.
def frombase($b):
def decimalValue:
if 48 <= . and . <= 57 then . - 48
elif 65 <= . and . <= 90 then . - 55 # (10+.-65)
elif 97 <= . and . <= 122 then . - 87 # (10+.-97)
else "decimalValue" | error
end;
reduce (explode|reverse[]|decimalValue) as $x ({p:1};
.value += (.p * $x)
| .p *= $b)
| .value ;
# To take advantage of gojq's arbitrary-precision integer arithmetic:
def power($b): . as $in | reduce range(0;$b) as $i (1; . * $in);
# If the input and $j are integers, then the result will be an integer.
def div($j):
(. - (. % j)) / $j;
# Convert an integer to a bitarray, least significant bit first
def bitwise:
recurse( if . >= 2 then div(2) else empty end) | . % 2;
# Essentially the inverse of bitwise,
# i.e. interpret an array of 0s and 1s (with least-significant-bit first ) as a decimal
def to_int:
. as $in
# state: [sum, power]
| reduce .[] as $i ([0, 1]; .[1] as $p | [.[0] + $p * $i, ($p * 2)])
| .[0];
# $x and $y and output are bitarrays
def xor($x;$y):
def lxor(a;b):
if (a==1 or b==1) and ((a==1 and b==1)|not) then 1
elif a == null then b
elif b == null then a
else 0
end;
if $x == [0] then $y
elif $y == [0] then $x
else
[ range(0; [($x|length), ($y|length)] | max) as $i
| lxor($x[$i]; $y[$i]) ]
end ;
# $x and $y and output are bitarrays
def xand($x;$y):
def lxand(a;b):
(a==1 and b==1) | 1 // 0;
if $x == [0] or $y == [0] then [0]
else
[range(0; [($x|length), ($y|length)] | min) as $i
| lxand($x[$i]; $y[$i]) ]
end ;
# shift right
def right($n): .[$n:];
def mask64: .[:64];
# input and output: a bitarray
def mult($int):
($int * to_int) | [bitwise];
def plus($int):
($int + to_int) | [bitwise];
def tabulate(stream):
reduce stream as $i ([]; .[$i] += 1)
| range(0;length) as $i
| " \($i) : \(.[$i] // 0)" ;
</syntaxhighlight>
'''Splitmix64'''
<syntaxhighlight lang="jq">
# input: a bitarray
def nextInt:
def Const1: "9e3779b97f4a7c15" | frombase(16) ;
def Const2: "bf58476d1ce4e5b9" | frombase(16) ;
def Const3: "94d049bb133111eb" | frombase(16) ;
(plus(Const1) | mask64)
| . as $state
| xor(.; right(30)) | mult(Const2) | mask64
| xor(.; right(27)) | mult(Const3) | mask64
| xor(.; right(31)) | mask64
| ., ($state|nextInt) ;
def randomInt64: [bitwise] | nextInt | to_int;
def randomReal:
pow(2;64) as $d
| [bitwise] | nextInt | to_int / $d;
### The tasks
(limit(5; 1234567 | randomInt64)),
"\nThe counts for 100,000 repetitions are:",
tabulate( limit(100; 987654321 | randomReal * 5 | floor) )
</syntaxhighlight>
{{output}}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
The counts for 100,000 repetitions are:
0 : 20027
1 : 19892
2 : 20073
3 : 19978
4 : 20030
</pre>
=={{header|Julia}}==
{{trans|Python}}
<
const C2 = 0xbf58476d1ce4e5b9
const C3 = 0x94d049bb133111eb
Line 311 ⟶ 905:
testSplitmix64()
</
<pre>
6457827717110365317
Line 321 ⟶ 915:
</pre>
=={{header|
<syntaxhighlight lang="mathematica">ClearAll[BitShiftLevelUint, MultiplyUint, GenerateRandomNumbers]
BitShiftLevelUint[z_, n_] := BitShiftRight[z, n]
MultiplyUint[z_, n_] := Mod[z n, 2^64]
GenerateRandomNumbers[st_, n_] := Module[{state = st},
Table[
state += 16^^9e3779b97f4a7c15;
state = Mod[state, 2^64];
z = MultiplyUint[BitXor[z, BitShiftLevelUint[z, 30]], 16^^bf58476d1ce4e5b9];
z = MultiplyUint[BitXor[z, BitShiftLevelUint[z, 27]], 16^^94d049bb133111eb];
Mod[BitXor[z, BitShiftLevelUint[z, 31]], 2^64]
,
{n}
]
]
GenerateRandomNumbers[1234567, 5]
nums = GenerateRandomNumbers[987654321, 10^5];
KeySort[Counts[Floor[5 nums/N[2^64]]]]</syntaxhighlight>
{{out}}
<pre>{6457827717110365317, 3203168211198807973, 9817491932198370423, 4593380528125082431, 16408922859458223821}
<|0->20027, 1->19892, 2->20073, 3->19978, 4->20030|></pre>
=={{header|Nim}}==
<syntaxhighlight lang="nim">import math, sequtils, strutils
const Two64 = 2.0^64
type Splitmix64 = object
state: uint64
func initSplitmix64(seed: uint64): Splitmix64 =
## Initialize a Splitmiax64 PRNG.
Splitmix64(state: seed)
func nextInt(r: var Splitmix64): uint64 =
## Return the next pseudorandom integer (actually a uint64 value).
r.state += 0x9e3779b97f4a7c15u
var z = r.state
z = (z xor z shr 30) * 0xbf58476d1ce4e5b9u
z = (z xor z shr 27) * 0x94d049bb133111ebu
result = z xor z shr 31
func nextFloat(r: var Splitmix64): float =
## Retunr the next pseudorandom float (between 0.0 and 1.0 excluded).
r.nextInt().float / Two64
when isMainModule:
echo "Seed = 1234567:"
var prng = initSplitmix64(1234567)
for i in 1..5:
echo i, ": ", ($prng.nextInt).align(20)
echo "\nSeed = 987654321:"
var counts: array[0..4, int]
prng = initSplitmix64(987654321)
for _ in 1..100_000:
inc counts[int(prng.nextFloat * 5)]
echo toSeq(counts.pairs).mapIt(($it[0]) & ": " & ($it[1])).join(", "</syntaxhighlight>
{{out}}
<pre>Seed = 1234567:
1: 6457827717110365317
2: 3203168211198807973
3: 9817491932198370423
4: 4593380528125082431
5: 16408922859458223821
Seed = 987654321:
0: 20027, 1: 19892, 2: 20073, 3: 19978, 4: 20030</pre>
=={{header|Object Pascal}}==
<syntaxhighlight lang="pascal">
program splitmix64;
Line 460 ⟶ 1,067:
Write(i, ': ', vec[i], ' ');
end.
</
<pre>
6457827717110365317
Line 468 ⟶ 1,075:
16408922859458223821
0: 20027 1: 19892 2: 20073 3: 19978 4: 20030
</pre>
=={{header|Odin}}==
Based on the C reference implementation.
<syntaxhighlight lang="odin">package main
import "core:fmt"
import "core:math"
TWO64 :f64: 1 << 64
SplitMix64 :: struct {
state: u64,
}
next_int :: proc(rng: ^SplitMix64) -> u64 {
rng.state += 0x9e3779b97f4a7c15
z := rng.state
z = (z ~ (z >> 30)) * 0xbf58476d1ce4e5b9
z = (z ~ (z >> 27)) * 0x94d049bb133111eb
return z ~ (z >> 31)
}
next_float :: proc(rng: ^SplitMix64) -> f64 {
return f64(next_int(rng)) / TWO64
}
main :: proc() {
rng := SplitMix64{1234567}
for i in 0..<5 {
fmt.println(next_int(&rng))
}
rng.state = 987654321
vec5 := [5]int{0,0,0,0,0}
for i in 0..<100000 {
j := int(math.floor(next_float(&rng) * 5.))
vec5[j] += 1
}
for v,i in vec5 {
fmt.printf("%d: %d ", i, v)
}
}
</syntaxhighlight>{{out}}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
0: 20027 1: 19892 2: 20073 3: 19978 4: 20030
</pre>
=={{header|Perl}}==
<syntaxhighlight lang="perl">use strict;
use warnings;
no warnings 'portable';
use feature 'say';
use Math::AnyNum qw(:overload);
package splitmix64 {
sub new {
my ($class, %opt) = @_;
bless {state => $opt{seed}}, $class;
}
sub next_int {
my ($self) = @_;
my $next = $self->{state} = ($self->{state} + 0x9e3779b97f4a7c15) & (2**64 - 1);
$next = ($next ^ ($next >> 30)) * 0xbf58476d1ce4e5b9 & (2**64 - 1);
$next = ($next ^ ($next >> 27)) * 0x94d049bb133111eb & (2**64 - 1);
($next ^ ($next >> 31)) & (2**64 - 1);
}
sub next_float {
my ($self) = @_;
$self->next_int / 2**64;
}
}
say 'Seed: 1234567, first 5 values:';
my $rng = splitmix64->new(seed => 1234567);
say $rng->next_int for 1 .. 5;
my %h;
say "\nSeed: 987654321, values histogram:";
$rng = splitmix64->new(seed => 987654321);
$h{int 5 * $rng->next_float}++ for 1 .. 100_000;
say "$_ $h{$_}" for sort keys %h;</syntaxhighlight>
{{out}}
<pre>Seed: 1234567, first 5 values:
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
Seed: 987654321, values histogram:
0 20027
1 19892
2 20073
3 19978
4 20030</pre>
=={{header|Phix}}==
As per [[Pseudo-random_numbers/PCG32#Phix]], resorting to mpfr/gmp
<syntaxhighlight lang="phix">
with javascript_semantics
include mpfr.e
mpz state = mpz_init(),
shift = mpz_init("0x9e3779b97f4a7c15"),
mult1 = mpz_init("0xbf58476d1ce4e5b9"),
mult2 = mpz_init("0x94d049bb133111eb"),
b64 = mpz_init("0x10000000000000000"), -- (truncate to 64 bits)
tmp = mpz_init(),
z = mpz_init()
procedure seed(integer num)
mpz_set_si(state,num)
end procedure
procedure next_int()
mpz_add(state, state, shift) -- state += shift
mpz_fdiv_r(state, state, b64) -- state := remainder(z,b64)
mpz_set(z, state) -- z := state
mpz_tdiv_q_2exp(tmp, z, 30) -- tmp := trunc(z/2^30)
mpz_xor(z, z, tmp) -- z := xor_bits(z,tmp)
mpz_mul(z, z, mult1) -- z *= mult1
mpz_fdiv_r(z, z, b64) -- z := remainder(z,b64)
mpz_tdiv_q_2exp(tmp, z, 27) -- tmp := trunc(z/2^27)
mpz_xor(z, z, tmp) -- z := xor_bits(z,tmp)
mpz_mul(z, z, mult2) -- z *= mult2
mpz_fdiv_r(z, z, b64) -- z := remainder(z,b64)
mpz_tdiv_q_2exp(tmp, z, 31) -- tmp := trunc(z/2^31)
mpz_xor(z, z, tmp) -- z := xor_bits(z,tmp)
-- (result left in z)
end procedure
function next_float()
next_int()
mpfr f = mpfr_init_set_z(z)
mpfr_div_z(f, f, b64)
return mpfr_get_d(f)
end function
seed(1234567)
for i=1 to 5 do
next_int()
printf(1,"%s\n",mpz_get_str(z))
end for
seed(987654321)
sequence r = repeat(0,5)
for i=1 to 100000 do
integer rdx = floor(next_float()*5)+1
r[rdx] += 1
end for
?r
</syntaxhighlight>
{{out}}
<pre>
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
{20027,19892,20073,19978,20030}
</pre>
=={{header|PicoLisp}}==
<
(de mod64 (N)
Line 503 ⟶ 1,280:
(roundf (* 5 (*/ (nextSplit) 1.0 18446744073709551616)))
1 ) )
(mapc println (sort R))</
{{out}}
<pre>
Line 522 ⟶ 1,299:
=={{header|Python}}==
<
C1 = 0x9e3779b97f4a7c15
C2 = 0xbf58476d1ce4e5b9
Line 561 ⟶ 1,338:
for i in range(100_000):
hist[int(random_gen.next_float() *5)] += 1
print(hist)</
{{out}}
Line 570 ⟶ 1,347:
16408922859458223821
{0: 20027, 1: 19892, 2: 20073, 3: 19978, 4: 20030}</pre>
=={{header|Quackery}}==
Note that Quackery does not have floating point, so this code uses rational numbers and approximates them to 16 places after the decimal point (when displayed as decimal fractions), so is at least as good as 64 bit floating point.
<syntaxhighlight lang="Quackery"> [ $ "bigrat.qky" loadfile ] now!
[ stack hex DEFACEABADFACADE ] is state ( --> s )
[ state replace ] is seed ( n ---> )
[ state take
hex 9E3779B97F4A7C15 + 64bits
dup state put
dup 30 >> ^
hex BF58476D1CE4E5B9 * 64bits
dup 27 >> ^
hex 94D049BB133111EB * 64bits
dup 31 >> ^ ] is nextint ( --> n )
[ nextint
hex 10000000000000000
10000000000000000 round ] is nextfrac ( --> n/d )
1234567 seed
5 times [ nextint echo cr ]
cr
987654321 seed
' [ 0 0 0 0 0 ]
100000 times
[ nextfrac 5 1 v* proper 2drop
2dup peek 1+ unrot poke ]
echo</syntaxhighlight>
{{out}}
<pre>6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
[ 20027 19892 20073 19978 20030 ]</pre>
=={{header|Raku}}==
{{works with|Rakudo|2020.07}}
<syntaxhighlight lang="raku"
has $!state;
Line 598 ⟶ 1,418:
say "\nSeed: 987654321; first 1e5 Rat values histogram";
$rng = splitmix64.new( :seed(987654321) );
say ( ($rng.next-rat * 5).floor xx 100_000 ).Bag;</
{{out}}
<pre>Seed: 1234567; first five Int values
Line 611 ⟶ 1,431:
=={{header|REXX}}==
<
numeric digits 200 /*ensure enough decimal digs for mult. */
parse arg n reps pick seed1 seed2 . /*obtain optional arguments from the CL*/
Line 661 ⟶ 1,481:
xor: parse arg a, b; $= /*perform a bit─wise XOR. */
do !=1 for length(a); $= $ || (substr(a,!,1) && substr(b,!,1) )
end /*!*/; return $</
{{out|output|text= when using the default inputs:}}
<pre>
Line 679 ⟶ 1,499:
3: 19,978
4: 20,030
</pre>
=={{header|RPL}}==
RPL offers hundreds of instructions and commands but, strangely, bitwise operations are limited to the set defined for the HP-16C RPN calculator in 1982.
So, to shift an integer n times, we can either stay in low gear, shifting one bit at a time:
≪ 1 SWAP '''START''' SR '''NEXT'''
≫ '<span style="color:blue">SRn</span>' STO
or play with the gearbox:
≪
8 MOD LAST / IP ROT <span style="color:grey">@ q, r = divmod(n,8)</span>
'''IF''' SWAP THEN 1 LAST '''START''' SRB '''NEXT END''' <span style="color:grey">@ q, r = divmod(n,8)</span>
'''IF''' SWAP '''THEN''' 1 LAST '''START''' SR '''NEXT END''' <span style="color:grey">@ shift & bit right, r times</span>
≫ '<span style="color:blue">SRn</span>' STO
The first version is less efficient in terms of response time, but more idiomatic because it takes much less time to type on a calculator keyboard.
{{works with|HP|28}}
≪ # 9E3779B97F4A7C15h 'STATE' STO+
<span style="color:green">STATE</span> DUP 30 SRn XOR # BF58476D1CE4E5B9h *
DUP 27 <span style="color:blue">SRn</span> XOR # 94D049BB133111EBh *
DUP 31 <span style="color:blue">SRn</span> XOR
≫ '<span style="color:blue">NEXTINT</span>' STO
≪ <span style="color:blue">NEXTINT</span> B→R 2 64 ^ /
≫ '<span style="color:blue">NEXTFLOAT</span>' STO
≪ # 1234567d '<span style="color:green">STATE</span>' STO
1 5 '''START''' <span style="color:blue">NEXTINT</span> '''NEXT'''
≫ '<span style="color:blue">TASK1</span>' STO
≪ { 5 } O CON
1 10000 '''START'''
<span style="color:blue">NEXTFLOAT</span> 5 * CEIL DUP2 GET 1 + PUT '''NEXT'''
≫ '<span style="color:blue">TASK2</span>' STO
The last task requirement takes too much time to be run on a calculator. On a emulator, we had to split it into 10 runs to not wake up the watchdog timer.
<span style="color:blue">TASK1</span>
# 987654321d '<span style="color:green">STATE</span>' STO
{ 5 } O CON
<span style="color:blue">TASK2</span> <span style="color:blue">TASK2</span> .. <span style="color:blue">TASK2</span> <span style="color:grey">@ 10 times</span>
{{out}}
<pre>
6: # 6457827717110365317d
5: # 3203168211198807973d
4: # 9817491932198370423d
3: # 4593380528125082431d
2: # 16408922859458223821d
1: [ 20027 19892 20073 19978 20030 ]
</pre>
=={{header|Ruby}}==
<syntaxhighlight lang="ruby">class Splitmix64
MASK64 = (1 << 64) - 1
C1, C2, C3 = 0x9e3779b97f4a7c15, 0xbf58476d1ce4e5b9, 0x94d049bb133111eb
def initialize(seed = 0) = @state = seed & MASK64
def rand_i
z = @state = (@state + C1) & MASK64
z = ((z ^ (z >> 30)) * C2) & MASK64
z = ((z ^ (z >> 27)) * C3) & MASK64
(z ^ (z >> 31)) & MASK64
end
def rand_f = rand_i.fdiv(1<<64)
end
rand_gen = Splitmix64.new(1234567)
5.times{ puts rand_gen.rand_i }
rand_gen = Splitmix64.new(987654321)
p 100_000.times.lazy.map{(rand_gen.rand_f * 5).floor}.tally.sort.to_h
</syntaxhighlight>
{{out}}
<pre>6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
{0=>20027, 1=>19892, 2=>20073, 3=>19978, 4=>20030}
</pre>
=={{header|Sidef}}==
{{trans|Perl}}
<syntaxhighlight lang="ruby">class Splitmix64(state) {
define (
mask64 = (2**64 - 1)
)
method next_int {
var n = (state = ((state + 0x9e3779b97f4a7c15) & mask64))
n = ((n ^ (n >> 30)) * 0xbf58476d1ce4e5b9 & mask64)
n = ((n ^ (n >> 27)) * 0x94d049bb133111eb & mask64)
(n ^ (n >> 31)) & mask64
}
method next_float {
self.next_int / (mask64+1)
}
}
say 'Seed: 1234567, first 5 values:'
var rng = Splitmix64(1234567)
5.of { rng.next_int.say }
say "\nSeed: 987654321, values histogram:"
var rng = Splitmix64(987654321)
var histogram = Bag(1e5.of { floor(5*rng.next_float) }...)
histogram.pairs.sort.each { .join(": ").say }</syntaxhighlight>
{{out}}
<pre>
Seed: 1234567, first 5 values:
6457827717110365317
3203168211198807973
9817491932198370423
4593380528125082431
16408922859458223821
Seed: 987654321, values histogram:
0: 20027
1: 19892
2: 20073
3: 19978
4: 20030
</pre>
Line 684 ⟶ 1,628:
{{libheader|Wren-big}}
No 64 bit integers so we use BigInt with a mask.
<
var Const1 = BigInt.fromBaseString("9e3779b97f4a7c15", 16)
Line 717 ⟶ 1,661:
}
System.print("\nThe counts for 100,000 repetitions are:")
for (i in 0..4) System.print(" %(i) : %(counts[i])")</
{{out}}
| |||