Examples of java.util.Random.nextDouble()

java.util.Random.nextDouble()
Returns the next pseudorandom, uniformly distributed {@code double} value between {@code 0.0} and{@code 1.0} from this random number generator's sequence.
The general contract of {@code nextDouble} is that one{@code double} value, chosen (approximately) uniformly from therange {@code 0.0d} (inclusive) to {@code 1.0d} (exclusive), ispseudorandomly generated and returned.
The method {@code nextDouble} is implemented by class {@code Random}as if by:
```
  {@code}public double nextDouble()  return (((long)next(26) << 27) + next(27)) / (double)(1L << 53); }}
```
The hedge "approximately" is used in the foregoing description only because the {@code next} method is only approximately an unbiasedsource of independently chosen bits. If it were a perfect source of randomly chosen bits, then the algorithm shown would choose {@code double} values from the stated range with perfect uniformity.
[In early versions of Java, the result was incorrectly calculated as:
```
  {@code return (((long)next(27) << 27) + next(27)) / (double)(1L << 54);}
```
This might seem to be equivalent, if not better, but in fact it introduced a large nonuniformity because of the bias in the rounding of floating-point numbers: it was three times as likely that the low-order bit of the significand would be 0 than that it would be 1! This nonuniformity probably doesn't matter much in practice, but we strive for perfection.] @return the next pseudorandom, uniformly distributed {@code double}value between {@code 0.0} and {@code 1.0} from thisrandom number generator's sequence @see Math#random

  testDouble(Double.NaN);
  testDouble(Double.NEGATIVE_INFINITY);
  testDouble(Double.POSITIVE_INFINITY);
  Random rand = new Random();
  for (int i = 0; i < 1000; i++) {
      testDouble(rand.nextDouble());
  }
    }


    public void testDouble(double v) throws Exception {
    }

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  testDoubleArray(new double[] { Double.POSITIVE_INFINITY });
  testDoubleArray(new double[] { Double.MAX_VALUE, Double.MIN_VALUE, Double.NaN, Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY });
  Random rand = new Random();
  double[] v = new double[100];
  for (int i = 0; i < v.length; ++i) {
      v[i] = rand.nextDouble();
  }
  testDoubleArray(v);
    }


    public void testDoubleArray(double[] v) throws Exception {

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        dsend = new double[length];
        drecv = new double[length];


        for (int i = 0; i < length; ++i) {
            dsend[i] = r.nextDouble();
            fsend[i] = r.nextFloat();
            lsend[i] = r.nextLong();
            isend[i] = r.nextInt();
            ssend[i] = (short) r.nextInt();
            csend[i] = (char) r.nextInt();

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    Random rand = new Random(System.currentTimeMillis()* this.hashCode()) ;


    text = txt ;


    pos = new double[2] ;
    pos[0] = rand.nextDouble() *100.0 ;
    pos[1] = rand.nextDouble() *100.0 ;


    direction = new double [2] ;
    direction[0] = rand.nextDouble() ;
    direction[1] = rand.nextDouble() ;

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    text = txt ;


    pos = new double[2] ;
    pos[0] = rand.nextDouble() *100.0 ;
    pos[1] = rand.nextDouble() *100.0 ;


    direction = new double [2] ;
    direction[0] = rand.nextDouble() ;
    direction[1] = rand.nextDouble() ;

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    pos = new double[2] ;
    pos[0] = rand.nextDouble() *100.0 ;
    pos[1] = rand.nextDouble() *100.0 ;


    direction = new double [2] ;
    direction[0] = rand.nextDouble() ;
    direction[1] = rand.nextDouble() ;


    accel = 0.0 ;
    speed = 1.0 ;

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    pos[0] = rand.nextDouble() *100.0 ;
    pos[1] = rand.nextDouble() *100.0 ;


    direction = new double [2] ;
    direction[0] = rand.nextDouble() ;
    direction[1] = rand.nextDouble() ;


    accel = 0.0 ;
    speed = 1.0 ;


    tag = 0 ;

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    for (pwnum=0; pwnum < npw; pwnum++) {


      password = new StringBuffer(pwl);


      pik = ran.nextDouble(); // random number [0,1]


      ranno = (long)(pik * data.getSigma()); // weight by sum of frequencies


      sum = 0;

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          break;  // exit while loop


        }


        pik = ran.nextDouble();


        ranno = (long)(pik * sum);


        sum = 0;

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    private double[] doubleArray(int count)
    {
        Random r = new Random(count);
        double[] result = new double[count];
        for (int i = 0; i < count; ++i) {
            double d = r.nextDouble();
            result[i] = r.nextBoolean() ? -d : d;
        }
        return result;
    }

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