## cern.jet.random Class Weibull

```java.lang.Object
|
+--cern.colt.PersistentObject
|
+--cern.jet.random.AbstractDistribution
|
+--cern.jet.random.AbstractContinousDistribution
|
+--cern.jet.random.Weibull
```
All Implemented Interfaces:
java.lang.Cloneable, cern.colt.function.DoubleFunction, cern.colt.function.IntFunction, java.io.Serializable

public class Weibull
extends AbstractContinousDistribution

Weibull Distribution. See the math definition.

p(x) = shape/scale*(x/scale)^(shape-1)*exp{-(x/scale)^shape} for x >= scale, shape > 0.

Note that mean is infinite if shape <= 1 and variance is infinite if shape <= 2.

Instance methods operate on a user supplied uniform random number generator; they are unsynchronized.

Static methods operate on a default uniform random number generator; they are synchronized.

Serialized Form

 Field Summary `protected  double` `scale` `protected  double` `shape` `protected static Weibull` `shared`

 Fields inherited from class cern.jet.random.AbstractDistribution `randomGenerator`

 Constructor Summary ```Weibull(double a, double b, RandomElement randomGenerator)```           Constructs a Pareto distribution.

 Method Summary ` double` `cdf(double x)`           Returns the cumulative distribution function. ` double` `nextDouble()`           Returns a random number from the distribution. ` double` ```nextDouble(double a, double b)```           Returns a random number from the distribution; bypasses the internal state. ` double` `pdf(double x)`           Returns the probability distribution function. ` void` ```setState(double a, double b)```           Sets the parameters. `static double` ```staticNextDouble(double a, double b)```           Returns a random number from the distribution with the given scale = k, and shape = alpha. ` java.lang.String` `toString()`           Returns a String representation of the receiver.

 Methods inherited from class cern.jet.random.AbstractDistribution `apply, apply, clone, getRandomGenerator, makeDefaultGenerator, nextInt, setRandomGenerator`

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

 Field Detail

### scale

`protected double scale`

### shape

`protected double shape`

### shared

`protected static Weibull shared`
 Constructor Detail

### Weibull

```public Weibull(double a,
double b,
RandomElement randomGenerator)```
Constructs a Pareto distribution.

 Method Detail

### cdf

`public double cdf(double x)`
Returns the cumulative distribution function.

### nextDouble

`public double nextDouble()`
Returns a random number from the distribution.

Specified by:
`nextDouble` in class `AbstractDistribution`

### nextDouble

```public double nextDouble(double a,
double b)```
Returns a random number from the distribution; bypasses the internal state.

### pdf

`public double pdf(double x)`
Returns the probability distribution function.

### setState

```public void setState(double a,
double b)```
Sets the parameters.

### staticNextDouble

```public static double staticNextDouble(double a,
double b)```
Returns a random number from the distribution with the given scale = k, and shape = alpha.

### toString

`public java.lang.String toString()`
Returns a String representation of the receiver.

Overrides:
`toString` in class `java.lang.Object`