ErfDifference

java.lang.Object
- org.apache.commons.numbers.gamma.ErfDifference

public final class ErfDifference
extends java.lang.Object

Computes the difference between error function values.

Field Summary

Fields
Modifier and Type Field Description

private static double X_CRIT
This number solves erf(x) = 0.5 within 1 ulp.

Constructor Summary

Constructors
Modifier Constructor Description

private ErfDifference()
Private constructor.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static double`	`value(double x1, double x2)`	The implementation uses either `Erf` or `Erfc`, depending on which provides the most precise result.

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

- Field Detail
  - X_CRIT
```
private static final double X_CRIT
```
    This number solves erf(x) = 0.5 within 1 ulp. More precisely, the current implementations of Erf.value(double) and Erfc.value(double) satisfy:
    
    Erf.value(X_CRIT) == 0.5,
    
    Erf.value(Math.nextUp(X_CRIT)) > 0.5,
    
    Erfc.value(X_CRIT) == 0.5, and
    
    Erfc.value(Math.nextUp(X_CRIT)) < 0.5
    See Also:
    
    Constant Field Values
- Constructor Detail
  - ErfDifference
```
private ErfDifference()
```
    Private constructor.
- Method Detail
  - value
```
public static double value(double x1,
                           double x2)
```
    The implementation uses either Erf or Erfc, depending on which provides the most precise result.
    
    Parameters:
    
    x1 - First value.
    
    x2 - Second value.
    
    Returns:
    
    Erf.value(x2) - Erf.value(x1).
    
    Throws:
    
    java.lang.ArithmeticException - if the algorithm fails to converge.