## cern.jet.random Class Exponential

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

public class Exponential
extends AbstractContinousDistribution

Exponential Distribution (aka Negative Exponential Distribution); See the math definition animated definition.

p(x) = lambda*exp(-x*lambda) for x >= 0, lambda > 0.

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` `lambda` `protected static Exponential` `shared`

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

 Constructor Summary ```Exponential(double lambda, RandomElement randomGenerator)```           Constructs a Negative Exponential distribution.

 Method Summary ` double` `cdf(double x)`           Returns the cumulative distribution function. ` double` `nextDouble()`           Returns a random number from the distribution. ` double` `nextDouble(double lambda)`           Returns a random number from the distribution; bypasses the internal state. ` double` `pdf(double x)`           Returns the probability distribution function. ` void` `setState(double lambda)`           Sets the mean. `static double` `staticNextDouble(double lambda)`           Returns a random number from the distribution with the given lambda. ` 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

### lambda

`protected double lambda`

### shared

`protected static Exponential shared`
 Constructor Detail

### Exponential

```public Exponential(double lambda,
RandomElement randomGenerator)```
Constructs a Negative Exponential 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 lambda)`
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 lambda)`
Sets the mean.

### staticNextDouble

`public static double staticNextDouble(double lambda)`
Returns a random number from the distribution with the given lambda.

### toString

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

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