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package com.github.phenomics.ontolib.utils;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

/**
 * 
MersenneTwister and MersenneTwisterFast
* *

* Version 22, based on version MT199937(99/10/29) of the Mersenne Twister algorithm found at * The Mersenne Twister Home Page, with * the initialization improved using the new 2002/1/26 initialization algorithm By Sean Luke, * October 2004. *

* *

* MersenneTwister is a drop-in subclass replacement for java.util.Random. It is properly * synchronized and can be used in a multithreaded environment. On modern VMs such as HotSpot, it is * approximately 1/3 slower than java.util.Random. *

* *

* MersenneTwisterFast is not a subclass of java.util.Random. It has the same public methods * as Random does, however, and it is algorithmically identical to MersenneTwister. * MersenneTwisterFast has hard-code inlined all of its methods directly, and made all of them final * (well, the ones of consequence anyway). Further, these methods are not synchronized, so * the same MersenneTwisterFast instance cannot be shared by multiple threads. But all this helps * MersenneTwisterFast achieve well over twice the speed of MersenneTwister. java.util.Random is * about 1/3 slower than MersenneTwisterFast. *

* *
About the Mersenne Twister
* *

* This is a Java version of the C-program for MT19937: Integer version. The MT19937 algorithm was * created by Makoto Matsumoto and Takuji Nishimura, who ask: "When you use this, send an email to: * [email protected] with an appropriate reference to your work". Indicate that this is a * translation of their algorithm into Java. *

* *

* Reference. Makato Matsumoto and Takuji Nishimura, "Mersenne Twister: A 623-Dimensionally * Equidistributed Uniform Pseudo-Random Number Generator", ACM Transactions on Modeling and. * Computer Simulation, Vol. 8, No. 1, January 1998, pp 3--30. *

* *
About this Version
* *

* Changes since V21: Minor documentation HTML fixes. *

* *

* Changes since V20: Added clearGuassian(). Modified stateEquals() to be synchronizd on both * objects for MersenneTwister, and changed its documentation. Added synchronization to both * setSeed() methods, to writeState(), and to readState() in MersenneTwister. Removed * synchronization from readObject() in MersenneTwister. *

* *

* Changes since V19: nextFloat(boolean, boolean) now returns float, not double. *

* *

* Changes since V18: Removed old final declarations, which used to potentially speed up the * code, but no longer. *

* *

* Changes since V17: Removed vestigial references to &= 0xffffffff which stemmed from * the original C code. The C code could not guarantee that ints were 32 bit, hence the masks. The * vestigial references in the Java code were likely optimized out anyway. *

* *

* Changes since V16: Added nextDouble(includeZero, includeOne) and nextFloat(includeZero, * includeOne) to allow for half-open, fully-closed, and fully-open intervals. *

* *

* Changes Since V15: Added serialVersionUID to quiet compiler warnings from Sun's overly * verbose compilers as of JDK 1.5. *

* *

* Changes Since V14: made strictfp, with StrictMath.log and StrictMath.sqrt in nextGaussian * instead of Math.log and Math.sqrt. This is largely just to be safe, as it presently makes no * difference in the speed, correctness, or results of the algorithm. *

* *

* Changes Since V13: clone() method CloneNotSupportedException removed. *

* *

* Changes Since V12: clone() method added. *

* *

* Changes Since V11: stateEquals(...) method added. MersenneTwisterFast is equal to other * MersenneTwisterFasts with identical state; likewise MersenneTwister is equal to other * MersenneTwister with identical state. This isn't equals(...) because that requires a contract of * immutability to compare by value. *

* *

* Changes Since V10: A documentation error suggested that setSeed(int[]) required an int[] * array 624 long. In fact, the array can be any non-zero length. The new version also checks for * this fact. *

* *

* Changes Since V9: readState(stream) and writeState(stream) provided. *

* *

* Changes Since V8: setSeed(int) was only using the first 28 bits of the seed; it should * have been 32 bits. For small-number seeds the behavior is identical. *

* *

* Changes Since V7: A documentation error in MersenneTwisterFast (but not MersenneTwister) * stated that nextDouble selects uniformly from the full-open interval [0,1]. It does not. * nextDouble's contract is identical across MersenneTwisterFast, MersenneTwister, and * java.util.Random, namely, selection in the half-open interval [0,1). That is, 1.0 should not be * returned. A similar contract exists in nextFloat. *

* *

* Changes Since V6: License has changed from LGPL to BSD. New timing information to compare * against java.util.Random. Recent versions of HotSpot have helped Random increase in speed to the * point where it is faster than MersenneTwister but slower than MersenneTwisterFast (which should * be the case, as it's a less complex algorithm but is synchronized). *

* *

* Changes Since V5: New empty constructor made to work the same as java.util.Random -- * namely, it seeds based on the current time in milliseconds. *

* *

* Changes Since V4: New initialization algorithms. See (see * * http://www.math.keio.ac.jp/matumoto/MT2002/emt19937ar.html) *

* *

* The MersenneTwister code is based on standard MT19937 C/C++ code by Takuji Nishimura, with * suggestions from Topher Cooper and Marc Rieffel, July 1997. The code was originally translated * into Java by Michael Lecuyer, January 1999, and the original code is Copyright (c) 1999 by * Michael Lecuyer. *

* *
Java notes
* *

* This implementation implements the bug fixes made in Java 1.2's version of Random, which means it * can be used with earlier versions of Java. See * the JDK 1.2 * java.util.Random documentation for further documentation on the random-number generation * contracts made. Additionally, there's an undocumented bug in the JDK java.util.Random.nextBytes() * method, which this code fixes. *

* *

* Just like java.util.Random, this generator accepts a long seed but doesn't use all of it. * java.util.Random uses 48 bits. The Mersenne Twister instead uses 32 bits (int size). So it's best * if your seed does not exceed the int range. *

* *

* MersenneTwister can be used reliably on JDK version 1.1.5 or above. Earlier Java versions have * serious bugs in java.util.Random; only MersenneTwisterFast (and not MersenneTwister nor * java.util.Random) should be used with them. *

* *
License
* *

* Copyright (c) 2003 by Sean Luke. Portions copyright (c) 1993 by Michael Lecuyer. All rights * reserved. *

* *

* Redistribution and use in source and binary forms, with or without modification, are permitted * provided that the following conditions are met: *

    *
  • Redistributions of source code must retain the above copyright notice, this list of * conditions and the following disclaimer. *
  • Redistributions in binary form must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other materials provided with * the distribution. *
  • Neither the name of the copyright owners, their employers, nor the names of its contributors * may be used to endorse or promote products derived from this software without specific prior * written permission. *
*

* *

* THIS SOFTWARE IS PROVIdED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNERS OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIdENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *

* * @version 22 */ public strictfp class MersenneTwister extends java.util.Random implements Serializable, Cloneable { // Serialization private static final long serialVersionUID = -4035832775130174188L; // locked as of Version 15 // Period parameters private static final int N = 624; private static final int M = 397; private static final int MATRIX_A = 0x9908b0df; // private static final * constant vector a private static final int UPPER_MASK = 0x80000000; // most significant w-r bits private static final int LOWER_MASK = 0x7fffffff; // least significant r bits // Tempering parameters private static final int TEMPERING_MASK_B = 0x9d2c5680; private static final int TEMPERING_MASK_C = 0xefc60000; private int[] mt; // the array for the state vector private int mti; // mti==N+1 means mt[N] is not initialized private int[] mag01; // a good initial seed (of int size, though stored in a long) // private static final long GOOD_SEED = 4357; /* * implemented here because there's a bug in Random's implementation of the Gaussian code (divide * by zero, and log(0), ugh!), yet its gaussian variables are private so we can't access them * here. :-( */ private double nextNextGaussian; private boolean haveNextNextGaussian; /* We're overriding all internal data, to my knowledge, so this should be okay */ @Override public Object clone() { try { MersenneTwister f = (MersenneTwister) (super.clone()); f.mt = mt.clone(); f.mag01 = mag01.clone(); return f; } catch (CloneNotSupportedException e) { throw new InternalError(); } // should never happen } /** * Returns true if the MersenneTwister's current internal state is equal to another * MersenneTwister. This is roughly the same as equals(other), except that it compares based on * value but does not guarantee the contract of immutability (obviously random number generators * are immutable). Note that this does NOT check to see if the internal gaussian storage is the * same for both. You can guarantee that the internal gaussian storage is the same (and so the * nextGaussian() methods will return the same values) by calling clearGaussian() on both objects. */ public synchronized boolean stateEquals(MersenneTwister other) { if (other == this) { return true; } if (other == null) { return false; } synchronized (other) { if (mti != other.mti) { return false; } for (int x = 0; x < mag01.length; x++) { if (mag01[x] != other.mag01[x]) { return false; } } for (int x = 0; x < mt.length; x++) { if (mt[x] != other.mt[x]) { return false; } } return true; } } /** Reads the entire state of the MersenneTwister RNG from the stream. */ public synchronized void readState(DataInputStream stream) throws IOException { int len = mt.length; for (int x = 0; x < len; x++) { mt[x] = stream.readInt(); } len = mag01.length; for (int x = 0; x < len; x++) { mag01[x] = stream.readInt(); } mti = stream.readInt(); nextNextGaussian = stream.readDouble(); haveNextNextGaussian = stream.readBoolean(); } /** Writes the entire state of the MersenneTwister RNG to the stream. */ public synchronized void writeState(DataOutputStream stream) throws IOException { int len = mt.length; for (int x = 0; x < len; x++) { stream.writeInt(mt[x]); } len = mag01.length; for (int x = 0; x < len; x++) { stream.writeInt(mag01[x]); } stream.writeInt(mti); stream.writeDouble(nextNextGaussian); stream.writeBoolean(haveNextNextGaussian); } /** * Constructor using the default seed. */ public MersenneTwister() { this(System.currentTimeMillis()); } /** * Constructor using a given seed. Though you pass this seed in as a long, it's best to make sure * it's actually an integer. */ public MersenneTwister(long seed) { super(seed); /* just in case */ setSeed(seed); } /** * Constructor using an array of integers as seed. Your array must have a non-zero length. Only * the first 624 integers in the array are used; if the array is shorter than this then integers * are repeatedly used in a wrap-around fashion. */ public MersenneTwister(int[] array) { super(System.currentTimeMillis()); /* pick something at random just in case */ setSeed(array); } /** * Initalize the pseudo random number generator. Don't pass in a long that's bigger than an int * (Mersenne Twister only uses the first 32 bits for its seed). */ public synchronized void setSeed(long seed) { // it's always good style to call super super.setSeed(seed); // Due to a bug in java.util.Random clear up to 1.2, we're // doing our own Gaussian variable. haveNextNextGaussian = false; mt = new int[N]; mag01 = new int[2]; mag01[0] = 0x0; mag01[1] = MATRIX_A; mt[0] = (int) (seed & 0xffffffff); mt[0] = (int) seed; for (mti = 1; mti < N; mti++) { mt[mti] = (1812433253 * (mt[mti - 1] ^ (mt[mti - 1] >>> 30)) + mti); /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */ /* In the previous versions, MSBs of the seed affect */ /* only MSBs of the array mt[]. */ /* 2002/01/09 modified by Makoto Matsumoto */ // mt[mti] &= 0xffffffff; /* for >32 bit machines */ } } /** * Sets the seed of the MersenneTwister using an array of integers. Your array must have a * non-zero length. Only the first 624 integers in the array are used; if the array is shorter * than this then integers are repeatedly used in a wrap-around fashion. */ public synchronized void setSeed(int[] array) { if (array.length == 0) { throw new IllegalArgumentException("Array length must be greater than zero"); } int i = 1; int j = 0; setSeed(19650218); int k = (N > array.length ? N : array.length); for (; k != 0; k--) { mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >>> 30)) * 1664525)) + array[j] + j; /* non linear */ // mt[i] &= 0xffffffff; /* for WORDSIZE > 32 machines */ i++; j++; if (i >= N) { mt[0] = mt[N - 1]; i = 1; } if (j >= array.length) { j = 0; } } for (k = N - 1; k != 0; k--) { mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >>> 30)) * 1566083941)) - i; /* non linear */ // mt[i] &= 0xffffffff; /* for WORDSIZE > 32 machines */ i++; if (i >= N) { mt[0] = mt[N - 1]; i = 1; } } mt[0] = 0x80000000; /* MSB is 1; assuring non-zero initial array */ } /** * Returns an integer with bits bits filled with a random number. */ protected synchronized int next(int bits) { int y; if (mti >= N) { // generate N words at one time int kk; final int[] mt = this.mt; // locals are slightly faster final int[] mag01 = this.mag01; // locals are slightly faster for (kk = 0; kk < N - M; kk++) { y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK); mt[kk] = mt[kk + M] ^ (y >>> 1) ^ mag01[y & 0x1]; } for (; kk < N - 1; kk++) { y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK); mt[kk] = mt[kk + (M - N)] ^ (y >>> 1) ^ mag01[y & 0x1]; } y = (mt[N - 1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N - 1] = mt[M - 1] ^ (y >>> 1) ^ mag01[y & 0x1]; mti = 0; } y = mt[mti++]; y ^= y >>> 11; // TEMPERING_SHIFT_U(y) y ^= (y << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(y) y ^= (y << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(y) y ^= (y >>> 18); // TEMPERING_SHIFT_L(y) return y >>> (32 - bits); // hope that's right! } /* * If you've got a truly old version of Java, you can omit these two next methods. */ private synchronized void writeObject(ObjectOutputStream out) throws IOException { // just so we're synchronized. out.defaultWriteObject(); } private void readObject(ObjectInputStream in) // readObject never needs to be Synchronized throws IOException, ClassNotFoundException { in.defaultReadObject(); } /** * This method is missing from jdk 1.0.x and below. JDK 1.1 includes this for us, but what the * heck. */ public boolean nextBoolean() { return next(1) != 0; } /** * This generates a coin flip with a probability probability of returning true, else * returning false. probability must be between 0.0 and 1.0, inclusive. Not as precise a * random real event as nextBoolean(double), but twice as fast. To explicitly use this, remember * you may need to cast to float first. */ public boolean nextBoolean(float probability) { if (probability < 0.0f || probability > 1.0f) { throw new IllegalArgumentException("probability must be between 0.0 and 1.0 inclusive."); } if (probability == 0.0f) { return false; // fix half-open issues } else if (probability == 1.0f) { return true; // fix half-open issues } return nextFloat() < probability; } /** * This generates a coin flip with a probability probability of returning true, else * returning false. probability must be between 0.0 and 1.0, inclusive. */ public boolean nextBoolean(double probability) { if (probability < 0.0 || probability > 1.0) { throw new IllegalArgumentException("probability must be between 0.0 and 1.0 inclusive."); } if (probability == 0.0) { return false; // fix half-open issues } else if (probability == 1.0) { return true; // fix half-open issues } return nextDouble() < probability; } /** * This method is missing from JDK 1.1 and below. JDK 1.2 includes this for us, but what the heck. */ public int nextInt(int n) { if (n <= 0) { throw new IllegalArgumentException("n must be positive, got: " + n); } if ((n & -n) == n) { return (int) ((n * (long) next(31)) >> 31); } int bits; int val; do { bits = next(31); val = bits % n; } while (bits - val + (n - 1) < 0); return val; } /** * This method is for completness' sake. Returns a long drawn uniformly from 0 to n-1. Suffice it * to say, n must be greater than 0, or an IllegalArgumentException is raised. */ public long nextLong(long n) { if (n <= 0) { throw new IllegalArgumentException("n must be positive, got: " + n); } long bits; long val; do { bits = (nextLong() >>> 1); val = bits % n; } while (bits - val + (n - 1) < 0); return val; } /** * A bug fix for versions of JDK 1.1 and below. JDK 1.2 fixes this for us, but what the heck. */ public double nextDouble() { return (((long) next(26) << 27) + next(27)) / (double) (1L << 53); } /** * Returns a double in the range from 0.0 to 1.0, possibly inclusive of 0.0 and 1.0 themselves. * Thus: * * * * * * * * * * * * * * * * * * * * * * * *
ExpressionInterval
nextDouble(false, false)(0.0, 1.0)
nextDouble(true, false)[0.0, 1.0)
nextDouble(false, true)(0.0, 1.0]
nextDouble(true, true)[0.0, 1.0]
Table of intervals
* *

* This version preserves all possible random values in the double range. *

*/ public double nextDouble(boolean includeZero, boolean includeOne) { double d = 0.0; do { d = nextDouble(); // grab a value, initially from half-open [0.0, 1.0) if (includeOne && nextBoolean()) { d += 1.0; // if includeOne, with 1/2 probability, push to [1.0, 2.0) } } while ((d > 1.0) || // everything above 1.0 is always invalid (!includeZero && d == 0.0)); // if we're not including zero, 0.0 is invalid return d; } /** * A bug fix for versions of JDK 1.1 and below. JDK 1.2 fixes this for us, but what the heck. */ public float nextFloat() { return next(24) / ((float) (1 << 24)); } /** * Returns a float in the range from 0.0f to 1.0f, possibly inclusive of 0.0f and 1.0f themselves. * Thus: * * * * * * * * * * * * * * * * * * * * * * * *
ExpressionInterval
nextFloat(false, false)(0.0f, 1.0f)
nextFloat(true, false)[0.0f, 1.0f)
nextFloat(false, true)(0.0f, 1.0f]
nextFloat(true, true)[0.0f, 1.0f]
Table of intervals
* *

* This version preserves all possible random values in the float range. *

*/ public float nextFloat(boolean includeZero, boolean includeOne) { float d = 0.0f; do { d = nextFloat(); // grab a value, initially from half-open [0.0f, 1.0f) if (includeOne && nextBoolean()) { d += 1.0f; // if includeOne, with 1/2 probability, push to [1.0f, 2.0f) } } while ((d > 1.0f) || // everything above 1.0f is always invalid (!includeZero && d == 0.0f)); // if we're not including zero, 0.0f is invalid return d; } /** * A bug fix for all versions of the JDK. The JDK appears to use all four bytes in an integer as * independent byte values! Totally wrong. I've submitted a bug report. */ public void nextBytes(byte[] bytes) { for (int x = 0; x < bytes.length; x++) { bytes[x] = (byte) next(8); } } /** For completeness' sake, though it's not in java.util.Random. */ public char nextChar() { // chars are 16-bit UniCode values return (char) (next(16)); } /** For completeness' sake, though it's not in java.util.Random. */ public short nextShort() { return (short) (next(16)); } /** For completeness' sake, though it's not in java.util.Random. */ public byte nextByte() { return (byte) (next(8)); } /** * Clears the internal gaussian variable from the RNG. You only need to do this in the rare case * that you need to guarantee that two RNGs have identical internal state. Otherwise, disregard * this method. See stateEquals(other). */ public synchronized void clearGaussian() { haveNextNextGaussian = false; } /** * A bug fix for all JDK code including 1.2. nextGaussian can theoretically ask for the log of 0 * and divide it by 0! See Java bug * * http://developer.java.sun.com/developer/bugParade/bugs/4254501.html */ public synchronized double nextGaussian() { if (haveNextNextGaussian) { haveNextNextGaussian = false; return nextNextGaussian; } else { double v1; double v2; double s; do { v1 = 2 * nextDouble() - 1; // between -1.0 and 1.0 v2 = 2 * nextDouble() - 1; // between -1.0 and 1.0 s = v1 * v1 + v2 * v2; } while (s >= 1 || s == 0); double multiplier = StrictMath.sqrt(-2 * StrictMath.log(s) / s); nextNextGaussian = v2 * multiplier; haveNextNextGaussian = true; return v1 * multiplier; } } /** * Tests the code. */ public static void main(String[] args) { int j; MersenneTwister r; // CORRECTNESS TEST // COMPARE WITH http://www.math.keio.ac.jp/matumoto/CODES/MT2002/mt19937ar.out r = new MersenneTwister(new int[] {0x123, 0x234, 0x345, 0x456}); System.out.println("Output of MersenneTwister with new (2002/1/26) seeding mechanism"); for (j = 0; j < 1000; j++) { // first, convert the int from signed to "unsigned" long l = (long) r.nextInt(); if (l < 0) { l += 4294967296L; // max int value } String s = String.valueOf(l); while (s.length() < 10) { s = " " + s; // buffer } System.out.print(s + " "); if (j % 5 == 4) { System.out.println(); } } // SPEED TEST final long seed = 4357L; long ms; System.out.println("\nTime to test grabbing 100000000 ints"); r = new MersenneTwister(seed); ms = System.currentTimeMillis(); int xx = 0; for (j = 0; j < 100000000; j++) { xx += r.nextInt(); } System.out.println( "Mersenne Twister: " + (System.currentTimeMillis() - ms) + " Ignore this: " + xx); System.out.println( "To compare this with java.util.Random, run this same test on MersenneTwisterFast."); System.out.println( "The comparison with Random is removed from MersenneTwister because it is a proper"); System.out.println( "subclass of Random and this unfairly makes some of Random's methods un-inlinable,"); System.out.println("so it would make Random look worse than it is."); // TEST TO COMPARE TYPE CONVERSION BETWEEN // MersenneTwisterFast.java AND MersenneTwister.java System.out.println("\nGrab the first 1000 booleans"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextBoolean() + " "); if (j % 8 == 7) { System.out.println(); } } if (!(j % 8 == 7)) { System.out.println(); } System.out.println("\nGrab 1000 booleans of increasing probability using nextBoolean(double)"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextBoolean(j / 999.0) + " "); if (j % 8 == 7) { System.out.println(); } } if (!(j % 8 == 7)) { System.out.println(); } System.out.println("\nGrab 1000 booleans of increasing probability using nextBoolean(float)"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextBoolean(j / 999.0f) + " "); if (j % 8 == 7) { System.out.println(); } } if (!(j % 8 == 7)) { System.out.println(); } byte[] bytes = new byte[1000]; System.out.println("\nGrab the first 1000 bytes using nextBytes"); r = new MersenneTwister(seed); r.nextBytes(bytes); for (j = 0; j < 1000; j++) { System.out.print(bytes[j] + " "); if (j % 16 == 15) { System.out.println(); } } if (!(j % 16 == 15)) { System.out.println(); } byte b; System.out.println("\nGrab the first 1000 bytes -- must be same as nextBytes"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print((b = r.nextByte()) + " "); if (b != bytes[j]) { System.out.print("BAD "); } if (j % 16 == 15) { System.out.println(); } } if (!(j % 16 == 15)) { System.out.println(); } System.out.println("\nGrab the first 1000 shorts"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextShort() + " "); if (j % 8 == 7) { System.out.println(); } } if (!(j % 8 == 7)) { System.out.println(); } System.out.println("\nGrab the first 1000 ints"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextInt() + " "); if (j % 4 == 3) { System.out.println(); } } if (!(j % 4 == 3)) { System.out.println(); } System.out.println("\nGrab the first 1000 ints of different sizes"); r = new MersenneTwister(seed); int max = 1; for (j = 0; j < 1000; j++) { System.out.print(r.nextInt(max) + " "); max *= 2; if (max <= 0) { max = 1; } if (j % 4 == 3) { System.out.println(); } } if (!(j % 4 == 3)) { System.out.println(); } System.out.println("\nGrab the first 1000 longs"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextLong() + " "); if (j % 3 == 2) { System.out.println(); } } if (!(j % 3 == 2)) { System.out.println(); } System.out.println("\nGrab the first 1000 longs of different sizes"); r = new MersenneTwister(seed); long max2 = 1; for (j = 0; j < 1000; j++) { System.out.print(r.nextLong(max2) + " "); max2 *= 2; if (max2 <= 0) { max2 = 1; } if (j % 4 == 3) { System.out.println(); } } if (!(j % 4 == 3)) { System.out.println(); } System.out.println("\nGrab the first 1000 floats"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextFloat() + " "); if (j % 4 == 3) { System.out.println(); } } if (!(j % 4 == 3)) { System.out.println(); } System.out.println("\nGrab the first 1000 doubles"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextDouble() + " "); if (j % 3 == 2) { System.out.println(); } } if (!(j % 3 == 2)) { System.out.println(); } System.out.println("\nGrab the first 1000 gaussian doubles"); r = new MersenneTwister(seed); for (j = 0; j < 1000; j++) { System.out.print(r.nextGaussian() + " "); if (j % 3 == 2) { System.out.println(); } } if (!(j % 3 == 2)) { System.out.println(); } } }




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