All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.scijava.util.MersenneTwisterFast Maven / Gradle / Ivy

Go to download

SciJava Common is a shared library for SciJava software. It provides a plugin framework, with an extensible mechanism for service discovery, backed by its own annotation processor, so that plugins can be loaded dynamically. It is used by downstream projects in the SciJava ecosystem, such as ImageJ and SCIFIO.

There is a newer version: 2.99.0
Show newest version
/*
 * #%L
 * SciJava Common shared library for SciJava software.
 * %%
 * Copyright (C) 2009 - 2014 Board of Regents of the University of
 * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
 * Institute of Molecular Cell Biology and Genetics.
 * %%
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. 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.
 * 
 * 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 HOLDERS 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.
 * #L%
 */

package org.scijava.util;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.Serializable;
import java.util.Random;

/** 
 * 

MersenneTwister and MersenneTwisterFast

*

Version 17, 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 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. * * @author Sean Luke * @version 17 */ @SuppressWarnings("all") public strictfp class MersenneTwisterFast implements Serializable, Cloneable { // Note: this class is hard-inlined in all of its methods. This makes some // of the methods well-nigh unreadable in their complexity. In fact, the // Mersenne Twister is fairly easy code to understand: if you're trying to // get a handle on the code, I strongly suggest looking at // MersenneTwister.java first. // -- Sean // Serialization private static final long serialVersionUID = -8219700664442619525L; // 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; private double __nextNextGaussian; private boolean __haveNextNextGaussian; /* We're overriding all internal data, to my knowledge, so this should be okay */ public Object clone() { try { MersenneTwisterFast f = (MersenneTwisterFast)(super.clone()); f.mt = (int[])(mt.clone()); f.mag01 = (int[])(mag01.clone()); return f; } catch (CloneNotSupportedException e) { throw new InternalError(); } // should never happen } public boolean stateEquals(Object o) { if (o==this) return true; if (o == null || !(o instanceof MersenneTwisterFast)) return false; MersenneTwisterFast other = (MersenneTwisterFast) o; if (mti != other.mti) return false; for(int x=0;x>> 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. */ synchronized public void setSeed(final int[] array) { if (array.length == 0) throw new IllegalArgumentException("Array length must be greater than zero"); int i, j, k; setSeed(19650218); i=1; j=0; 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 */ } public final int nextInt() { 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; } public final short nextShort() { 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 (short)(y >>> 16); } public final char nextChar() { 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 (char)(y >>> 16); } public final boolean nextBoolean() { 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 (boolean)((y >>> 31) != 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 final boolean nextBoolean(final float probability) { int y; 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 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 >>> 8) / ((float)(1 << 24)) < 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 final boolean nextBoolean(final double probability) { int y; int z; 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 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) 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++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+M] ^ (z >>> 1) ^ mag01[z & 0x1]; } for (; kk < N-1; kk++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (z >>> 1) ^ mag01[z & 0x1]; } z = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N-1] = mt[M-1] ^ (z >>> 1) ^ mag01[z & 0x1]; mti = 0; } z = mt[mti++]; z ^= z >>> 11; // TEMPERING_SHIFT_U(z) z ^= (z << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(z) z ^= (z << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(z) z ^= (z >>> 18); // TEMPERING_SHIFT_L(z) /* derived from nextDouble documentation in jdk 1.2 docs, see top */ return ((((long)(y >>> 6)) << 27) + (z >>> 5)) / (double)(1L << 53) < probability; } public final byte nextByte() { 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 (byte)(y >>> 24); } public final void nextBytes(byte[] bytes) { int y; for (int x=0;x= 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) bytes[x] = (byte)(y >>> 24); } } public final long nextLong() { int y; int z; 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) 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++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+M] ^ (z >>> 1) ^ mag01[z & 0x1]; } for (; kk < N-1; kk++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (z >>> 1) ^ mag01[z & 0x1]; } z = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N-1] = mt[M-1] ^ (z >>> 1) ^ mag01[z & 0x1]; mti = 0; } z = mt[mti++]; z ^= z >>> 11; // TEMPERING_SHIFT_U(z) z ^= (z << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(z) z ^= (z << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(z) z ^= (z >>> 18); // TEMPERING_SHIFT_L(z) return (((long)y) << 32) + (long)z; } /** Returns a long drawn uniformly from 0 to n-1. Suffice it to say, n must be > 0, or an IllegalArgumentException is raised. */ public final long nextLong(final long n) { if (n<=0) throw new IllegalArgumentException("n must be positive, got: " + n); long bits, val; do { int y; int z; 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) 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++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+M] ^ (z >>> 1) ^ mag01[z & 0x1]; } for (; kk < N-1; kk++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (z >>> 1) ^ mag01[z & 0x1]; } z = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N-1] = mt[M-1] ^ (z >>> 1) ^ mag01[z & 0x1]; mti = 0; } z = mt[mti++]; z ^= z >>> 11; // TEMPERING_SHIFT_U(z) z ^= (z << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(z) z ^= (z << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(z) z ^= (z >>> 18); // TEMPERING_SHIFT_L(z) bits = (((((long)y) << 32) + (long)z) >>> 1); val = bits % n; } while (bits - val + (n-1) < 0); return val; } /** Returns a random double in the half-open range from [0.0,1.0). Thus 0.0 is a valid result but 1.0 is not. */ public final double nextDouble() { int y; int z; 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) 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++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+M] ^ (z >>> 1) ^ mag01[z & 0x1]; } for (; kk < N-1; kk++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (z >>> 1) ^ mag01[z & 0x1]; } z = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N-1] = mt[M-1] ^ (z >>> 1) ^ mag01[z & 0x1]; mti = 0; } z = mt[mti++]; z ^= z >>> 11; // TEMPERING_SHIFT_U(z) z ^= (z << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(z) z ^= (z << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(z) z ^= (z >>> 18); // TEMPERING_SHIFT_L(z) /* derived from nextDouble documentation in jdk 1.2 docs, see top */ return ((((long)(y >>> 6)) << 27) + (z >>> 5)) / (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]

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; } public final double nextGaussian() { if (__haveNextNextGaussian) { __haveNextNextGaussian = false; return __nextNextGaussian; } else { double v1, v2, s; do { int y; int z; int a; int b; 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) 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++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+M] ^ (z >>> 1) ^ mag01[z & 0x1]; } for (; kk < N-1; kk++) { z = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (z >>> 1) ^ mag01[z & 0x1]; } z = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N-1] = mt[M-1] ^ (z >>> 1) ^ mag01[z & 0x1]; mti = 0; } z = mt[mti++]; z ^= z >>> 11; // TEMPERING_SHIFT_U(z) z ^= (z << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(z) z ^= (z << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(z) z ^= (z >>> 18); // TEMPERING_SHIFT_L(z) 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++) { a = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+M] ^ (a >>> 1) ^ mag01[a & 0x1]; } for (; kk < N-1; kk++) { a = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (a >>> 1) ^ mag01[a & 0x1]; } a = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N-1] = mt[M-1] ^ (a >>> 1) ^ mag01[a & 0x1]; mti = 0; } a = mt[mti++]; a ^= a >>> 11; // TEMPERING_SHIFT_U(a) a ^= (a << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(a) a ^= (a << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(a) a ^= (a >>> 18); // TEMPERING_SHIFT_L(a) 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++) { b = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+M] ^ (b >>> 1) ^ mag01[b & 0x1]; } for (; kk < N-1; kk++) { b = (mt[kk] & UPPER_MASK) | (mt[kk+1] & LOWER_MASK); mt[kk] = mt[kk+(M-N)] ^ (b >>> 1) ^ mag01[b & 0x1]; } b = (mt[N-1] & UPPER_MASK) | (mt[0] & LOWER_MASK); mt[N-1] = mt[M-1] ^ (b >>> 1) ^ mag01[b & 0x1]; mti = 0; } b = mt[mti++]; b ^= b >>> 11; // TEMPERING_SHIFT_U(b) b ^= (b << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(b) b ^= (b << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(b) b ^= (b >>> 18); // TEMPERING_SHIFT_L(b) /* derived from nextDouble documentation in jdk 1.2 docs, see top */ v1 = 2 * (((((long)(y >>> 6)) << 27) + (z >>> 5)) / (double)(1L << 53)) - 1; v2 = 2 * (((((long)(a >>> 6)) << 27) + (b >>> 5)) / (double)(1L << 53)) - 1; 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; } } /** Returns a random float in the half-open range from [0.0f,1.0f). Thus 0.0f is a valid result but 1.0f is not. */ public final float nextFloat() { 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 >>> 8) / ((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]

This version preserves all possible random values in the float range. */ public double 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; } /** Returns an integer drawn uniformly from 0 to n-1. Suffice it to say, n must be > 0, or an IllegalArgumentException is raised. */ public final int nextInt(final int n) { if (n<=0) throw new IllegalArgumentException("n must be positive, got: " + n); if ((n & -n) == n) // i.e., n is a power of 2 { 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 (int)((n * (long) (y >>> 1) ) >> 31); } int bits, val; do { 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) bits = (y >>> 1); val = bits % n; } while(bits - val + (n-1) < 0); return val; } /** * Tests the code. */ public static void main(String args[]) { int j; MersenneTwisterFast r; // CORRECTNESS TEST // COMPARE WITH http://www.math.keio.ac.jp/matumoto/CODES/MT2002/mt19937ar.out r = new MersenneTwisterFast(new int[]{0x123, 0x234, 0x345, 0x456}); System.out.println("Output of MersenneTwisterFast 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 = 4357; int xx; long ms; System.out.println("\nTime to test grabbing 100000000 ints"); Random rr = new Random(SEED); xx = 0; ms = System.currentTimeMillis(); for (j = 0; j < 100000000; j++) xx += rr.nextInt(); System.out.println("java.util.Random: " + (System.currentTimeMillis()-ms) + " Ignore this: " + xx); r = new MersenneTwisterFast(SEED); ms = System.currentTimeMillis(); xx=0; for (j = 0; j < 100000000; j++) xx += r.nextInt(); System.out.println("Mersenne Twister Fast: " + (System.currentTimeMillis()-ms) + " Ignore this: " + xx); // TEST TO COMPARE TYPE CONVERSION BETWEEN // MersenneTwisterFast.java AND MersenneTwister.java System.out.println("\nGrab the first 1000 booleans"); r = new MersenneTwisterFast(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 MersenneTwisterFast(SEED); for (j = 0; j < 1000; j++) { System.out.print(r.nextBoolean((double)(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 MersenneTwisterFast(SEED); for (j = 0; j < 1000; j++) { System.out.print(r.nextBoolean((float)(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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 MersenneTwisterFast(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(); } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy