Move random number generators to new folder.
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package java.util;
import java.math.BigInteger;
import java.util.concurrent.atomic.AtomicLong;
/**
* A generator of uniform pseudorandom values applicable for use in
* (among other contexts) isolated parallel computations that may
* generate subtasks. Class {@code MRG32k3a} implements
* interfaces {@link java.util.Rng} and {@link java.util.AbstractArbitrarilyJumpableRng},
* and therefore supports methods for producing pseudorandomly chosen
* numbers of type {@code int}, {@code long}, {@code float}, and {@code double}
* as well as creating new {@code Xoroshiro128PlusMRG32k3a} objects
* by "jumping" or "leaping".
*
* <p>Instances {@code Xoroshiro128Plus} are <em>not</em> thread-safe.
* They are designed to be used so that each thread as its own instance.
* The methods {@link #jump} and {@link #leap} and {@link #jumps} and {@link #leaps}
* can be used to construct new instances of {@code Xoroshiro128Plus} that traverse
* other parts of the state cycle.
*
* <p>Instances of {@code MRG32k3a} are not cryptographically
* secure. Consider instead using {@link java.security.SecureRandom}
* in security-sensitive applications. Additionally,
* default-constructed instances do not use a cryptographically random
* seed unless the {@linkplain System#getProperty system property}
* {@code java.util.secureRandomSeed} is set to {@code true}.
*
* @author Guy Steele
* @since 1.9
*/
public final class MRG32k3a extends AbstractArbitrarilyJumpableRng {
/*
* Implementation Overview.
*
* See http://simul.iro.umontreal.ca/rng/MRG32k3a.c .
*
* File organization: First the non-public methods that constitute
* the main algorithm, then the main public methods, followed by
* some custom spliterator classes needed for stream methods.
*/
private final static double norm1 = 2.328306549295728e-10;
private final static double norm2 = 2.328318824698632e-10;
private final static double m1 = 4294967087.0;
private final static double m2 = 4294944443.0;
private final static double a12 = 1403580.0;
private final static double a13n = 810728.0;
private final static double a21 = 527612.0;
private final static double a23n = 1370589.0;
private final static int m1_deficit = 209;
// IllegalArgumentException messages
private static final String BadLogDistance = "logDistance must be non-negative and not greater than 192";
/**
* The per-instance state.
The seeds for s10, s11, s12 must be integers in [0, m1 - 1] and not all 0.
The seeds for s20, s21, s22 must be integers in [0, m2 - 1] and not all 0.
*/
private double s10, s11, s12,
s20, s21, s22;
/**
* The seed generator for default constructors.
*/
private static final AtomicLong defaultGen = new AtomicLong(RngSupport.initialSeed());
/*
32-bits Random number generator U(0,1): MRG32k3a
Author: Pierre L'Ecuyer,
Source: Good Parameter Sets for Combined Multiple Recursive Random
Number Generators,
Shorter version in Operations Research,
47, 1 (1999), 159--164.
---------------------------------------------------------
*/
private void nextState() {
/* Component 1 */
double p1 = a12 * s11 - a13n * s10;
double k1 = p1 / m1; p1 -= k1 * m1; if (p1 < 0.0) p1 += m1;
s10 = s11; s11 = s12; s12 = p1;
/* Component 2 */
double p2 = a21 * s22 - a23n * s20;
double k2 = p2 / m2; p2 -= k2 * m2; if (p2 < 0.0) p2 += m2;
s20 = s21; s21 = s22; s22 = p2;
}
/**
* The form of nextInt used by IntStream Spliterators.
* Exactly the same as long version, except for types.
*
* @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive), must not equal origin
* @return a pseudorandom value
*/
private int internalNextInt(int origin, int bound) {
if (origin < bound) {
final int n = bound - origin;
final int m = n - 1;
if (n > 0) {
int r;
for (int u = (int)nextDouble() >>> 1;
u + m + ((m1_deficit + 1) >>> 1) - (r = u % n) < 0;
u = (int)nextDouble() >>> 1)
;
return (r + origin);
} else {
return RngSupport.boundedNextInt(this, origin, bound);
}
} else {
return nextInt();
}
}
private int internalNextInt(int bound) {
// Specialize internalNextInt for origin == 0, bound > 0
final int n = bound;
final int m = n - 1;
int r;
for (int u = (int)nextDouble() >>> 1;
u + m + ((m1_deficit + 1) >>> 1) - (r = u % n) < 0;
u = (int)nextDouble() >>> 1)
;
return r;
}
/**
* All arguments must be known to be nonnegative integral values
* less than the appropriate modulus.
*/
private MRG32k3a(double s10, double s11, double s12,
double s20, double s21, double s22) {
this.s10 = s10; this.s11 = s11; this.s12 = s12;
this.s20 = s20; this.s21 = s21; this.s22 = s22;
if ((s10 == 0.0) && (s11 == 0.0) && (s12 == 0.0)) {
this.s10 = this.s11 = this.s12 = 12345.0;
}
if ((s20 == 0.0) && (s21 == 0.0) && (s22 == 0.0)) {
this.s20 = this.s21 = this.s21 = 12345.0;
}
}
/* ---------------- public methods ---------------- */
/**
* Creates a new MRG32k3a instance using six specified {@code int}
* initial seed values. MRG32k3a instances created with the same
* seeds in the same program generate identical sequences of values.
* If all six seed values are zero, the generator is seeded to a
* widely used initialization of MRG32k3a: all six state variables
* are set to 12345.
*
* @param s10 the first seed value for the first subgenerator
* @param s11 the second seed value for the first subgenerator
* @param s12 the third seed value for the first subgenerator
* @param s20 the first seed value for the second subgenerator
* @param s21 the second seed value for the second subgenerator
* @param s22 the third seed value for the second subgenerator
*/
public MRG32k3a(int s10, int s11, int s12,
int s20, int s21, int s22) {
this(((double)(((long)s10) & 0x00000000ffffffffL)) % m1,
((double)(((long)s11) & 0x00000000ffffffffL)) % m1,
((double)(((long)s12) & 0x00000000ffffffffL)) % m1,
((double)(((long)s20) & 0x00000000ffffffffL)) % m2,
((double)(((long)s21) & 0x00000000ffffffffL)) % m2,
((double)(((long)s22) & 0x00000000ffffffffL)) % m2);
}
/**
* Creates a new MRG32k3a instance using the specified
* initial seed. MRG32k3a instances created with the same
* seed in the same program generate identical sequences of values.
* An argument of 0 seeds the generator to a widely used initialization
* of MRG32k3a: all six state variables are set to 12345.
*
* @param seed the initial seed
*/
public MRG32k3a(long seed) {
this((double)((seed & 0x7FF) + 12345),
(double)(((seed >>> 11) & 0x7FF) + 12345),
(double)(((seed >>> 22) & 0x7FF) + 12345),
(double)(((seed >>> 33) & 0x7FF) + 12345),
(double)(((seed >>> 44) & 0x7FF) + 12345),
(double)((seed >>> 55) + 12345));
}
/**
* Creates a new MRG32k3a instance that is likely to
* generate sequences of values that are statistically independent
* of those of any other instances in the current program; and
* may, and typically does, vary across program invocations.
*/
public MRG32k3a() {
this(defaultGen.getAndAdd(RngSupport.GOLDEN_RATIO_64));
}
/**
* Creates a new instance of {@code Xoshiro256StarStar} using the specified array of
* initial seed bytes. Instances of {@code Xoshiro256StarStar} created with the same
* seed array in the same program execution generate identical sequences of values.
*
* @param seed the initial seed
*/
public MRG32k3a(byte[] seed) {
// Convert the seed to 6 int values.
int[] data = RngSupport.convertSeedBytesToInts(seed, 6, 0);
int s10 = data[0], s11 = data[1], s12 = data[2];
int s20 = data[3], s21 = data[4], s22 = data[5];
this.s10 = ((double)(((long)s10) & 0x00000000ffffffffL)) % m1;
this.s11 = ((double)(((long)s11) & 0x00000000ffffffffL)) % m1;
this.s12 = ((double)(((long)s12) & 0x00000000ffffffffL)) % m1;
this.s20 = ((double)(((long)s20) & 0x00000000ffffffffL)) % m2;
this.s21 = ((double)(((long)s21) & 0x00000000ffffffffL)) % m2;
this.s22 = ((double)(((long)s22) & 0x00000000ffffffffL)) % m2;
if ((s10 == 0.0) && (s11 == 0.0) && (s12 == 0.0)) {
this.s10 = this.s11 = this.s12 = 12345.0;
}
if ((s20 == 0.0) && (s21 == 0.0) && (s22 == 0.0)) {
this.s20 = this.s21 = this.s21 = 12345.0;
}
}
public MRG32k3a copy() { return new MRG32k3a(s10, s11, s12, s20, s21, s22); }
/**
* Returns a pseudorandom {@code double} value between zero
* (exclusive) and one (exclusive).
*
* @return a pseudorandom {@code double} value between zero
* (exclusive) and one (exclusive)
*/
public double nextOpenDouble() {
nextState();
double p1 = s12, p2 = s22;
if (p1 <= p2)
return ((p1 - p2 + m1) * norm1);
else
return ((p1 - p2) * norm1);
}
/**
* Returns a pseudorandom {@code double} value between zero
* (inclusive) and one (exclusive).
*
* @return a pseudorandom {@code double} value between zero
* (inclusive) and one (exclusive)
*/
public double nextDouble() {
nextState();
double p1 = s12, p2 = s22;
final double p = p1 * norm1 - p2 * norm2;
if (p < 0.0) return (p + 1.0);
else return p;
}
/**
* Returns a pseudorandom {@code float} value between zero
* (inclusive) and one (exclusive).
*
* @return a pseudorandom {@code float} value between zero
* (inclusive) and one (exclusive)
*/
public float nextFloat() {
return (float)nextDouble();
}
/**
* Returns a pseudorandom {@code int} value.
*
* @return a pseudorandom {@code int} value
*/
public int nextInt() {
return (internalNextInt(0x10000) << 16) | internalNextInt(0x10000);
}
/**
* Returns a pseudorandom {@code long} value.
*
* @return a pseudorandom {@code long} value
*/
public long nextLong() {
return (((long)internalNextInt(0x200000) << 43) |
((long)internalNextInt(0x200000) << 22) |
((long)internalNextInt(0x400000)));
}
// Period is (m1**3 - 1)(m2**3 - 1)/2, or approximately 2**191.
static BigInteger calculateThePeriod() {
BigInteger bigm1 = BigInteger.valueOf((long)m1);
BigInteger bigm2 = BigInteger.valueOf((long)m2);
BigInteger t1 = bigm1.multiply(bigm1).multiply(bigm1).subtract(BigInteger.ONE);
BigInteger t2 = bigm2.multiply(bigm2).multiply(bigm2).subtract(BigInteger.ONE);
return t1.shiftRight(1).multiply(t2);
}
static final BigInteger thePeriod = calculateThePeriod();
public BigInteger period() { return thePeriod; }
// Jump and leap distances recommended in Section 1.3 of this paper:
// Pierre L'Ecuyer, Richard Simard, E. Jack Chen, and W. David Kelton.
// An Object-Oriented Random-Number Package with Many Long Streams and Substreams.
// Operations Research 50, 6 (Nov--Dec 2002), 1073--1075.
public double defaultJumpDistance() { return 0x1.0p76; } // 2**76
public double defaultLeapDistance() { return 0x1.0p127; } // 2**127
public void jump(double distance) {
if (distance < 0.0 || Double.isInfinite(distance) || distance != Math.floor(distance))
throw new IllegalArgumentException("jump distance must be a nonnegative finite integer");
// We will compute a jump transformation (s => M s) for each LCG.
// We initialize each transformation to the identity transformation.
// Each will be turned into the d'th power of the corresponding base transformation.
long m1_00 = 1, m1_01 = 0, m1_02 = 0,
m1_10 = 0, m1_11 = 1, m1_12 = 0,
m1_20 = 0, m1_21 = 0, m1_22 = 1;
long m2_00 = 1, m2_01 = 0, m2_02 = 0,
m2_10 = 0, m2_11 = 1, m2_12 = 0,
m2_20 = 0, m2_21 = 0, m2_22 = 1;
// These are the base transformations, which will be repeatedly squared,
// and composed with the computed transformations for each 1-bit in distance.
long t1_00 = 0, t1_01 = 1, t1_02 = 0,
t1_10 = 0, t1_11 = 0, t1_12 = 1,
t1_20 = -(long)a13n, t1_21 = (long)a12, t1_22 = 0;
long t2_00 = 0, t2_01 = 1, t2_02 = 0,
t2_10 = 0, t2_11 = 0, t2_12 = 1,
t2_20 = -(long)a23n, t2_21 = (long)a21, t2_22 = 0;
while (distance > 0.0) {
final double dhalf = 0.5 * distance;
if (Math.floor(dhalf) != dhalf) {
// distance is odd: accumulate current squaring
final long n1_00 = m1_00 * t1_00 + m1_01 * t1_10 + m1_02 * t1_20;
final long n1_01 = m1_00 * t1_01 + m1_01 * t1_11 + m1_02 * t1_21;
final long n1_02 = m1_00 * t1_02 + m1_01 * t1_12 + m1_02 * t1_22;
final long n1_10 = m1_10 * t1_00 + m1_11 * t1_10 + m1_12 * t1_20;
final long n1_11 = m1_10 * t1_01 + m1_11 * t1_11 + m1_12 * t1_21;
final long n1_12 = m1_10 * t1_02 + m1_11 * t1_12 + m1_12 * t1_22;
final long n1_20 = m1_20 * t1_00 + m1_21 * t1_10 + m1_22 * t1_20;
final long n1_21 = m1_20 * t1_01 + m1_21 * t1_11 + m1_22 * t1_21;
final long n1_22 = m1_20 * t1_02 + m1_21 * t1_12 + m1_22 * t1_22;
m1_00 = Math.floorMod(n1_00, (long)m1);
m1_01 = Math.floorMod(n1_01, (long)m1);
m1_02 = Math.floorMod(n1_02, (long)m1);
m1_10 = Math.floorMod(n1_10, (long)m1);
m1_11 = Math.floorMod(n1_11, (long)m1);
m1_12 = Math.floorMod(n1_12, (long)m1);
m1_20 = Math.floorMod(n1_20, (long)m1);
m1_21 = Math.floorMod(n1_21, (long)m1);
m1_22 = Math.floorMod(n1_22, (long)m1);
final long n2_00 = m2_00 * t2_00 + m2_01 * t2_10 + m2_02 * t2_20;
final long n2_01 = m2_00 * t2_01 + m2_01 * t2_11 + m2_02 * t2_21;
final long n2_02 = m2_00 * t2_02 + m2_01 * t2_12 + m2_02 * t2_22;
final long n2_10 = m2_10 * t2_00 + m2_11 * t2_10 + m2_12 * t2_20;
final long n2_11 = m2_10 * t2_01 + m2_11 * t2_11 + m2_12 * t2_21;
final long n2_12 = m2_10 * t2_02 + m2_11 * t2_12 + m2_12 * t2_22;
final long n2_20 = m2_20 * t2_00 + m2_21 * t2_10 + m2_22 * t2_20;
final long n2_21 = m2_20 * t2_01 + m2_21 * t2_11 + m2_22 * t2_21;
final long n2_22 = m2_20 * t2_02 + m2_21 * t2_12 + m2_22 * t2_22;
m2_00 = Math.floorMod(n2_00, (long)m2);
m2_01 = Math.floorMod(n2_01, (long)m2);
m2_02 = Math.floorMod(n2_02, (long)m2);
m2_10 = Math.floorMod(n2_10, (long)m2);
m2_11 = Math.floorMod(n2_11, (long)m2);
m2_12 = Math.floorMod(n2_12, (long)m2);
m2_20 = Math.floorMod(n2_20, (long)m2);
m2_21 = Math.floorMod(n2_21, (long)m2);
m2_22 = Math.floorMod(n2_22, (long)m2);
}
// Square the base transformations.
{
final long z1_00 = m1_00 * m1_00 + m1_01 * m1_10 + m1_02 * m1_20;
final long z1_01 = m1_00 * m1_01 + m1_01 * m1_11 + m1_02 * m1_21;
final long z1_02 = m1_00 * m1_02 + m1_01 * m1_12 + m1_02 * m1_22;
final long z1_10 = m1_10 * m1_00 + m1_11 * m1_10 + m1_12 * m1_20;
final long z1_11 = m1_10 * m1_01 + m1_11 * m1_11 + m1_12 * m1_21;
final long z1_12 = m1_10 * m1_02 + m1_11 * m1_12 + m1_12 * m1_22;
final long z1_20 = m1_20 * m1_00 + m1_21 * m1_10 + m1_22 * m1_20;
final long z1_21 = m1_20 * m1_01 + m1_21 * m1_11 + m1_22 * m1_21;
final long z1_22 = m1_20 * m1_02 + m1_21 * m1_12 + m1_22 * m1_22;
m1_00 = Math.floorMod(z1_00, (long)m1);
m1_01 = Math.floorMod(z1_01, (long)m1);
m1_02 = Math.floorMod(z1_02, (long)m1);
m1_10 = Math.floorMod(z1_10, (long)m1);
m1_11 = Math.floorMod(z1_11, (long)m1);
m1_12 = Math.floorMod(z1_12, (long)m1);
m1_20 = Math.floorMod(z1_20, (long)m1);
m1_21 = Math.floorMod(z1_21, (long)m1);
m1_22 = Math.floorMod(z1_22, (long)m1);
final long z2_00 = m2_00 * m2_00 + m2_01 * m2_10 + m2_02 * m2_20;
final long z2_01 = m2_00 * m2_01 + m2_01 * m2_11 + m2_02 * m2_21;
final long z2_02 = m2_00 * m2_02 + m2_01 * m2_12 + m2_02 * m2_22;
final long z2_10 = m2_10 * m2_00 + m2_11 * m2_10 + m2_12 * m2_20;
final long z2_11 = m2_10 * m2_01 + m2_11 * m2_11 + m2_12 * m2_21;
final long z2_12 = m2_10 * m2_02 + m2_11 * m2_12 + m2_12 * m2_22;
final long z2_20 = m2_20 * m2_00 + m2_21 * m2_10 + m2_22 * m2_20;
final long z2_21 = m2_20 * m2_01 + m2_21 * m2_11 + m2_22 * m2_21;
final long z2_22 = m2_20 * m2_02 + m2_21 * m2_12 + m2_22 * m2_22;
m2_00 = Math.floorMod(z2_00, (long)m2);
m2_01 = Math.floorMod(z2_01, (long)m2);
m2_02 = Math.floorMod(z2_02, (long)m2);
m2_10 = Math.floorMod(z2_10, (long)m2);
m2_11 = Math.floorMod(z2_11, (long)m2);
m2_12 = Math.floorMod(z2_12, (long)m2);
m2_20 = Math.floorMod(z2_20, (long)m2);
m2_21 = Math.floorMod(z2_21, (long)m2);
m2_22 = Math.floorMod(z2_22, (long)m2);
}
// Divide distance by 2.
distance = dhalf;
}
final long w10 = m1_00 * (long)s10 + m1_01 * (long)s11 + m1_02 * (long)s12;
final long w11 = m1_10 * (long)s10 + m1_11 * (long)s11 + m1_12 * (long)s12;
final long w12 = m1_20 * (long)s10 + m1_21 * (long)s11 + m1_22 * (long)s12;
s10 = Math.floorMod(w10, (long)m1);
s11 = Math.floorMod(w11, (long)m1);
s12 = Math.floorMod(w12, (long)m1);
final long w20 = m2_00 * (long)s20 + m2_01 * (long)s21 + m2_02 * (long)s22;
final long w21 = m2_10 * (long)s20 + m2_11 * (long)s21 + m2_12 * (long)s22;
final long w22 = m2_20 * (long)s20 + m2_21 * (long)s21 + m2_22 * (long)s22;
s20 = Math.floorMod(w20, (long)m2);
s21 = Math.floorMod(w21, (long)m2);
s22 = Math.floorMod(w22, (long)m2);
}
/**
* Alter the state of this pseudorandom number generator so as to
* jump forward a distance equal to 2<sup>{@code logDistance}</sup>
* within its state cycle.
*
* @param logDistance the base-2 logarithm of the distance to jump
* forward within the state cycle. Must be non-negative and
* not greater than 192.
* @throws IllegalArgumentException if {@code logDistance} is
* less than zero or 2<sup>{@code logDistance}</sup> is
* greater than the period of this generator
*/
public void jumpPowerOfTwo(int logDistance) {
if (logDistance < 0 || logDistance > 192)
throw new IllegalArgumentException(BadLogDistance);
jump(Math.scalb(1.0, logDistance));
}
}