public class Erf extends Object
public static double erf(double x)
erf(x) = 2/√π 0∫x e-t2dt
This implementation computes erf(x) using the
regularized gamma function
,
following Erf, equation (3)
The value returned is always between -1 and 1 (inclusive).
If abs(x) > 40
, then erf(x)
is indistinguishable from
either 1 or -1 as a double, so the appropriate extreme value is returned.
x
- the value.MaxCountExceededException
- if the algorithm fails to converge.Gamma.regularizedGammaP(double, double, double, int)
public static double erfc(double x)
erfc(x) = 2/√π x∫∞ e-t2dt
= 1 - erf(x)
This implementation computes erfc(x) using the
regularized gamma function
,
following Erf, equation (3).
The value returned is always between 0 and 2 (inclusive).
If abs(x) > 40
, then erf(x)
is indistinguishable from
either 0 or 2 as a double, so the appropriate extreme value is returned.
x
- the valueMaxCountExceededException
- if the algorithm fails to converge.Gamma.regularizedGammaQ(double, double, double, int)
public static double erf(double x1, double x2)
x1
- the first valuex2
- the second valueCopyright © 2003-2012 Apache Software Foundation. All Rights Reserved.