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Last active August 18, 2020 19:12
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Reproducing random integer generation in different languages
#include <iostream>
#include <chrono>
#include <random>
#include <iomanip>
int main ()
{
std::mt19937 generator (0);
std::cout << generator() << std::endl;
std::cout << generator() << std::endl;
std::cout << generator() << std::endl;
// Output:
// 2357136044
// 2546248239
return 0;
}
import std.random;
void main () {
Mt19937 gen;
gen.seed(0);
import std.stdio;
writeln(gen.front);
}
// 2357136044
#!/usr/bin/perl -w
use strict;
use feature 'say';
use Math::Random::MT;
my $r = Math::Random::MT->new(0);
say $r->irand();
say $r->irand();
# Output:
# 2357136044
# 2546248239
import numpy as np
np.random.seed(0)
print(np.random.randint(0, 4294967295)) # not sure if max value is correct
print(np.random.randint(0, 4294967295))
# Output:
# 2357136044
# 2546248239
r = Random.new(0)
p r.rand(4294967296)
p r.rand(4294967296)
# Output:
# 2357136044
# 2546248239
# Don't know who the author is sadly
def _int32(x):
# Get the 32 least significant bits.
return int(0xFFFFFFFF & x)
class MT19937:
def __init__(self, seed):
# Initialize the index to 0
self.index = 624
self.mt = [0] * 624
self.mt[0] = seed # Initialize the initial state to the seed
for i in range(1, 624):
self.mt[i] = _int32(
1812433253 * (self.mt[i - 1] ^ self.mt[i - 1] >> 30) + i)
def extract_number(self):
if self.index >= 624:
self.twist()
y = self.mt[self.index]
# Right shift by 11 bits
y = y ^ y >> 11
# Shift y left by 7 and take the bitwise and of 2636928640
y = y ^ y << 7 & 2636928640
# Shift y left by 15 and take the bitwise and of y and 4022730752
y = y ^ y << 15 & 4022730752
# Right shift by 18 bits
y = y ^ y >> 18
self.index = self.index + 1
return _int32(y)
def twist(self):
for i in range(624):
# Get the most significant bit and add it to the less significant
# bits of the next number
y = _int32((self.mt[i] & 0x80000000) +
(self.mt[(i + 1) % 624] & 0x7fffffff))
self.mt[i] = self.mt[(i + 397) % 624] ^ y >> 1
if y % 2 != 0:
self.mt[i] = self.mt[i] ^ 0x9908b0df
self.index = 0
#test
m = MT19937(0)
print(m.extract_number())
print(m.extract_number())
# Output:
# 2357136044
# 2546248239
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