Esempio n. 1
0
  /** 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();
  }