public class ErrorFunction
extends java.lang.Object
Modifier | Constructor and Description |
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protected |
ErrorFunction()
Make class non-instantiable but inheritable.
|
Modifier and Type | Method and Description |
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protected static double |
calerf(double x,
int jint)
Calculate value of Gaussian error function.
|
static double |
errorFunction(double x)
Error function.
|
static double |
errorFunctionComplement(double x)
Error function complement.
|
static double |
errorFunctionComplementInverseBad(double x) |
static double |
errorFunctionInverse(double z)
Inverse error function.
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static double |
errorFunctionInverseBad(double x)
Percentage points of error function distribution.
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protected ErrorFunction()
protected static double calerf(double x, int jint)
x
- jint
- Selects type of error function evaluation.
= 0: error function
= 1: complement of error function.
= 2: exp(xx) * complement of error function.The program returns erfc=0 for x > XBIG (see below); erfcx = XINF for x < XNEG; and erfcx = 0 for x >= XMAX.
The main computation evaluates near-minimax approximations from "Rational Chebyshev approximations for the error function" by W. J. Cody, Math. Comp., 1969, PP. 631-638. This java code is a straightforward translation of W. J. Cody's Fortran CALERF function.
public static double errorFunction(double x)
x
- Error function argument.public static double errorFunctionComplement(double x)
x
- Error function argument.public static double errorFunctionInverse(double z)
z
- Probability for which matching percentage point
of error function is desired.The percentage point is computed using the relationship between the error function and the normal distribution.
public static double errorFunctionInverseBad(double x)
x
- Parameter for which percentage point is desired.The approximations used here come from in Blair, J. M. et. al., "Rational Chebyshev Approximations for the Inverse Error Function," Math Comp. Vol. 30, No. 136, Oct. 1976, pp. 827-830.
public static double errorFunctionComplementInverseBad(double x)