GammaPD (JMSL Numerical Library)

java.lang.Object
- com.imsl.stat.distributions.ProbabilityDistribution
- - com.imsl.stat.distributions.GammaPD

All Implemented Interfaces:

Serializable, Cloneable
```
public class GammaPD
extends ProbabilityDistribution
implements Serializable, Cloneable
```
The gamma probability distribution

See Also:
Example, Serialized Form

Constructor Summary

Constructors
Constructor and Description

GammaPD()
Constructor for the gamma probability distribution

Constructors
Constructor and Description
`GammaPD()` Constructor for the gamma probability distribution

Method Summary

Methods
Modifier and Type	Method and Description
`double[]`	`getParameterLowerBounds()` Returns the lower bounds for the shape and scale parameters of the gamma distribution.
`double[]`	`getParameterUpperBounds()` Returns the upper bounds for the shape and scale parameters of the gamma distribution.
`double`	`pdf(double x, double[] params)` Returns the value of the gamma probability density function.

Methods inherited from class com.imsl.stat.distributions.ProbabilityDistribution
getNumberOfParameters, getPDFGradientApproximation, getPDFHessianApproximation, getRangeOfX, setRangeOfX

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

- Constructor Detail
  - GammaPD
```
public GammaPD()
```
    Constructor for the gamma probability distribution
- Method Detail
  - getParameterLowerBounds
```
public double[] getParameterLowerBounds()
```
    Returns the lower bounds for the shape and scale parameters of the gamma distribution.
    
    Specified by:
    
    getParameterLowerBounds in class ProbabilityDistribution
    
    Returns:
    a double array containing the lower bounds
  - getParameterUpperBounds
```
public double[] getParameterUpperBounds()
```
    Returns the upper bounds for the shape and scale parameters of the gamma distribution.
    
    Specified by:
    
    getParameterUpperBounds in class ProbabilityDistribution
    
    Returns:
    a double array containing the upper bounds
  - pdf
```
public double pdf(double x,
         double[] params)
```
    Returns the value of the gamma probability density function.
    The probability density function of the gamma distribution is
    
    $f(x; a, b) = x^{a - 1} frac{1}{{b^{a} Gamma (a)}} e^{ - {x}/{b}}$
    where a is the shape parameter and b is the scale parameter.
    
    Specified by:
    
    pdf in class ProbabilityDistribution
    
    Parameters:
    x - a double value in the range of X
    params - a double array containing values of the parameters, with params[0]=a and params[1]=b
    
    Returns:
    a double value equal to the probability density at x given the parameter values

Class GammaPD

Constructor Summary

Method Summary

Methods inherited from class com.imsl.stat.distributions.ProbabilityDistribution

Methods inherited from class java.lang.Object

Constructor Detail

GammaPD

Method Detail

getParameterLowerBounds

getParameterUpperBounds

pdf