Rand (randomz 0.0.2 API)

java.lang.Object
- mikera.util.Rand

```
public final class Rand
extends Object
```

Constructor Summary

Constructors
Constructor and Description

Rand()

Constructors
Constructor and Description
`Rand()`

Method Summary

Methods
Modifier and Type	Method and Description
`static int`	`best(int r, int n, int s)` sum of best r from n s-sided dice
`static double`	`binary(double mean)`
`static void`	`binarySample(double[] temp, int offset, int length)` Randomises the temp array to 0.0 or 1.0 according to the probabilities in the array
`static void`	`binarySample(float[] temp, int offset, int length)`
`static double`	`binomialChance(int r, int n, double p)`
`static boolean`	`chance(double d)` Returns true with a given probability
`static boolean`	`chance(float d)` Returns true with a given probability
`static void`	`chooseIntegers(int[] dest, int destOffset, int length, int maxValue)` Chooses a set of distinct integers from a range 0 to maxValue-1 Resulting integers are sorted
`static double`	`combinations(int r, int n)`
`static double`	`cumulativeBinomialChance(int r, int n, double p)` Returns the probability of up to r successes in n trials, each with probability of success p
`static int`	`d(int sides)` simulates a dice roll with the given number of sides
`static int`	`d(int number, int sides)` Calculates the sum of (number) x (sides)-sided dice
`static int`	`d10()`
`static int`	`d100()`
`static int`	`d12()`
`static int`	`d20()`
`static int`	`d3()`
`static int`	`d4()`
`static int`	`d6()`
`static int`	`d8()`
`static double`	`exp(double mean)` Returns a random sample from an exponential distribution
`static double`	`factorial(int n)`
`static double`	`factorialRatio(int n, int r)` Calculates n!/r! Avoids the overhead of calculating the terms which cancel out
`static void`	`fillBinary(double[] data, int start, int length, double mean)`
`static void`	`fillBinary(float[] d, int start, int length)`
`static void`	`fillGaussian(double[] d, int start, int length, double u, double sd)`
`static void`	`fillGaussian(float[] d, int start, int length, float u, float sd)`
`static void`	`fillUniform(float[] d, int start, int length)`
`static int`	`geom(double p)` Returns a sample from a Geometric distribution Discrete distribution with decay rate p Mean = (1-p) / p Probability mass function for each integer output k = p.(1-p)^k
`static int`	`indexFromWeights(double[] probabilities)`
`static double`	`n(double u, double sd)` Generates a normal distributed number with the given mean and standard deviation
`static boolean`	`nextBoolean()` Sample a random boolean value with 50% chance
`static byte`	`nextByte()` Sample a random (signed) byte
`static char`	`nextChar()` Sample a random char
`static double`	`nextDouble()` Returns standard double in range [0..1)
`static float`	`nextFloat()` Sample a random float in range [0..1)
`static double`	`nextGaussian()`
`static int`	`nextInt()` Sample a random signed 32-bit integer
`static char`	`nextLetter()` Sample a random lowercase letter
`static String`	`nextLetterString(int length)`
`static long`	`nextLong()` Gets a long random value
`static short`	`nextShort()` Sample a random signed short value
`static String`	`nextString()`
`static int`	`otherIndex(int i, int max)` Return a random index between 0 and max (exclusive) not equal to i
`static <T> T`	`pick(Collection<T> ts)` Picks a random item from a given collection
`static <T> T`	`pick(List<T> ts)` Picks a random item from a given list
`static <T> T`	`pick(T[] ts)` Picks a random item from a given array
`static int`	`po(double mean)` Poisson distribution
`static int`	`po(int numerator, int denominator)` Draw a sample from the possion distribution with parameter = numerator / denominator
`static int`	`r(int s)` Random number from zero to s-1
`static void`	`randIntegers(int[] dest, int destOffset, int length, int maxValue)` Creates a set of n random integers from a range of 0 to maxValue-1
`static int`	`range(int n1, int n2)` Returns random number uniformly distributed in inclusive [n1, n2] range.
`static int`	`round(double d)` Randomly rounds to the nearest integer
`static <T> void`	`shuffle(T[] ts)` Randomly shuffles all elements in a given array
`static int`	`sig(float x)` logistic sigmoid probability
`static double`	`sigmoid(double a)` Sigmoid function
`static double`	`u()` Sample a random uniform double in range [0..1)
`static double`	`u(double max)` Sample a random uniform double in range [0..max)
`static double`	`u(double min, double max)` Sample a random uniform double in the range [min..max)
`static int`	`xorShift32(int a)` XORShift algorithm - credit to George Marsaglia!
`static long`	`xorShift64(long a)` XORShift algorithm - very fast psuedo-random number generator Credit to George Marsaglia!

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- Rand
```
public Rand()
```

Method Detail

nextLong
```
public static final long nextLong()
```
Gets a long random value

Returns:
Random long value based on static state

xorShift64
```
public static final long xorShift64(long a)
```
XORShift algorithm - very fast psuedo-random number generator Credit to George Marsaglia!

Parameters:
a - Initial state

Returns:
new state

xorShift32
```
public static final int xorShift32(int a)
```
XORShift algorithm - credit to George Marsaglia!

Parameters:
a - Initial state

Returns:
new state

chance
```
public static boolean chance(double d)
```
Returns true with a given probability

Parameters:
d -

Returns:

chance
```
public static boolean chance(float d)
```
Returns true with a given probability

Parameters:
d -

Returns:

best

public static int best(int r,
       int n,
       int s)

sum of best r from n s-sided dice

Parameters:: r -; n -; s -
Returns:

sigmoid

public static double sigmoid(double a)

Sigmoid function

sig
```
public static int sig(float x)
```
logistic sigmoid probability

Parameters:
x -

Returns:

po
```
public static int po(double mean)
```
Poisson distribution

Parameters:
mean - The mean of the poisson distrubution to sample from

Returns:

po
```
public static int po(int numerator,
     int denominator)
```
Draw a sample from the possion distribution with parameter = numerator / denominator

Parameters:
numerator -
denominator -

Returns:

d
```
public static int d(int number,
    int sides)
```
Calculates the sum of (number) x (sides)-sided dice

Parameters:
number -
sides -

Returns:

factorial

public static double factorial(int n)

factorialRatio
```
public static double factorialRatio(int n,
                    int r)
```
Calculates n!/r! Avoids the overhead of calculating the terms which cancel out

Parameters:
n -
r -

Returns:

cumulativeBinomialChance
```
public static double cumulativeBinomialChance(int r,
                              int n,
                              double p)
```
Returns the probability of up to r successes in n trials, each with probability of success p

Parameters:
r -
n -
p -

Returns:

combinations

public static double combinations(int r,
                  int n)

binomialChance

public static double binomialChance(int r,
                    int n,
                    double p)

exp
```
public static double exp(double mean)
```
Returns a random sample from an exponential distribution

Parameters:
mean -

Returns:

geom
```
public static int geom(double p)
```
Returns a sample from a Geometric distribution Discrete distribution with decay rate p Mean = (1-p) / p Probability mass function for each integer output k = p.(1-p)^k

nextInt
```
public static final int nextInt()
```
Sample a random signed 32-bit integer

Returns:

nextShort
```
public static final short nextShort()
```
Sample a random signed short value

Returns:

nextChar
```
public static final char nextChar()
```
Sample a random char

Returns:

nextLetterString

public static final String nextLetterString(int length)

nextByte
```
public static final byte nextByte()
```
Sample a random (signed) byte

Returns:

nextBoolean
```
public static boolean nextBoolean()
```
Sample a random boolean value with 50% chance

Returns:

nextLetter
```
public static final char nextLetter()
```
Sample a random lowercase letter

Returns:

r
```
public static final int r(int s)
```
Random number from zero to s-1

Parameters:
s - Upper bound (excluded)

Returns:

otherIndex
```
public static final int otherIndex(int i,
             int max)
```
Return a random index between 0 and max (exclusive) not equal to i

nextDouble
```
public static final double nextDouble()
```
Returns standard double in range [0..1)

Returns:

nextFloat
```
public static final float nextFloat()
```
Sample a random float in range [0..1)

Returns:

u
```
public static final double u()
```
Sample a random uniform double in range [0..1)

Returns:

u
```
public static final double u(double max)
```
Sample a random uniform double in range [0..max)

Parameters:
max -

Returns:

u
```
public static final double u(double min,
       double max)
```
Sample a random uniform double in the range [min..max)

Parameters:
min -
max -

Returns:

round
```
public static final int round(double d)
```
Randomly rounds to the nearest integer

range
```
public static final int range(int n1,
        int n2)
```
Returns random number uniformly distributed in inclusive [n1, n2] range. It is allowed to have to n1 > n2, or n1 < n2, or n1 == n2.

d
```
public static final int d(int sides)
```
simulates a dice roll with the given number of sides

Parameters:
sides -

Returns:

d3
```
public static final int d3()
```

d4
```
public static final int d4()
```

d6
```
public static final int d6()
```

d8
```
public static final int d8()
```

d10
```
public static final int d10()
```

d12
```
public static final int d12()
```

d20
```
public static final int d20()
```

d100
```
public static final int d100()
```

n
```
public static double n(double u,
       double sd)
```
Generates a normal distributed number with the given mean and standard deviation

Parameters:
u - Mean
sd - Standard deviation

Returns:

nextGaussian
```
public static double nextGaussian()
```

nextString
```
public static String nextString()
```

shuffle
```
public static <T> void shuffle(T[] ts)
```
Randomly shuffles all elements in a given array

chooseIntegers

public static void chooseIntegers(int[] dest,
                  int destOffset,
                  int length,
                  int maxValue)

Chooses a set of distinct integers from a range 0 to maxValue-1 Resulting integers are sorted

randIntegers

public static void randIntegers(int[] dest,
                int destOffset,
                int length,
                int maxValue)

Creates a set of n random integers from a range of 0 to maxValue-1

pick
```
public static <T> T pick(T[] ts)
```
Picks a random item from a given array

pick
```
public static <T> T pick(List<T> ts)
```
Picks a random item from a given list

pick
```
public static <T> T pick(Collection<T> ts)
```
Picks a random item from a given collection

fillUniform

public static void fillUniform(float[] d,
               int start,
               int length)

fillBinary

public static void fillBinary(float[] d,
              int start,
              int length)

fillGaussian

public static void fillGaussian(float[] d,
                int start,
                int length,
                float u,
                float sd)

fillGaussian

public static void fillGaussian(double[] d,
                int start,
                int length,
                double u,
                double sd)

fillBinary

public static void fillBinary(double[] data,
              int start,
              int length,
              double mean)

binary

public static double binary(double mean)

binarySample

public static void binarySample(float[] temp,
                int offset,
                int length)

binarySample
```
public static void binarySample(double[] temp,
                int offset,
                int length)
```
Randomises the temp array to 0.0 or 1.0 according to the probabilities in the array

Parameters:
temp -
offset -
length -

indexFromWeights

public static int indexFromWeights(double[] probabilities)

Class Rand

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Rand

Method Detail

nextLong

xorShift64

xorShift32

chance

chance

best

sigmoid

sig

po

po

d

factorial

factorialRatio

cumulativeBinomialChance

combinations

binomialChance

exp

geom

nextInt

nextShort

nextChar

nextLetterString

nextByte

nextBoolean

nextLetter

r

otherIndex

nextDouble

nextFloat

u

u

u

round

range

d

d3

d4

d6

d8

d10

d12

d20

d100

n

nextGaussian

nextString

shuffle

chooseIntegers

randIntegers

pick

pick

pick

fillUniform

fillBinary

fillGaussian

fillGaussian

fillBinary

binary

binarySample

binarySample

indexFromWeights