## Class GammaRatio

• public final class GammaRatio
extends Object
Ratio of Gamma functions.

$\frac{\Gamma(a)}{\Gamma(b)}$

This code has been adapted from:

• The Boost c++ implementation <boost/math/special_functions/gamma.hpp>.
Since:
1.1
Boost C++ Ratios of Gamma Functions
• ### Method Summary

All Methods
Modifier and Type Method Description
static double delta​(double a, double delta)
Computes the ratio of gamma functions of a value and an offset value.
static double value​(double a, double b)
Computes the ratio of gamma functions of two values.
• ### Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
• ### Method Detail

• #### value

public static double value​(double a,
double b)
Computes the ratio of gamma functions of two values.

$\frac{\Gamma(a)}{\Gamma(b)}$

If either argument is <= 0 or infinite then the result is NaN.

Parameters:
a - Argument a (must be positive finite).
b - Argument b (must be positive finite).
Returns:
$$\Gamma(a) / \Gamma(b)$$
• #### delta

public static double delta​(double a,
double delta)
Computes the ratio of gamma functions of a value and an offset value.

$\frac{\Gamma(a)}{\Gamma(a + delta)}$

Note that the result is calculated accurately even when delta is small compared to a: indeed even if a+delta ~ a. The function is typically used when a is large and delta is very small.

Parameters:
a - Argument.
delta - Argument.
Returns:
$$\Gamma(a) / \Gamma(a + delta)$$