distributions
Class Derf

java.lang.Object
  |
  +--distributions.Derf

public class Derf
extends java.lang.Object

This class contains a Java translation of FORTRAN routines written by W. Fullerton of LANL to calculate the double precision error function and the double precision complementary error function.


Constructor Summary
Derf()
           
 
Method Summary
static double dcsevl(double x, double[] cs, int n)
          This method evaluates the n-term Chebyshev series cs at x.
static double derf(double x)
          This method calculates the double precision error function.
static double derfc(double x)
          This method calculates the double precision complementary error function.
static int initds(double[] os, int nos, double eta)
          This method determines the number of terms needed in an orthogonal polynomial series so that it meets a specified accuracy.
static double sign(double a, double b)
           This method implements the FORTRAN sign (not sin) function.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Derf

public Derf()
Method Detail

derf

public static double derf(double x)
This method calculates the double precision error function. It is a Java translation of the FORTRAN routine derf written by W. Fullerton of LANL. The FORTRAN version is part of the SLATEC library of numerical analysis routines.

Steve Verrill translated the FORTRAN code (updated 6/18/92) into Java. This translation was performed on February 21, 2002.

Parameters:
x -

derfc

public static double derfc(double x)
This method calculates the double precision complementary error function. It is a Java translation of the FORTRAN routine derfc written by W. Fullerton of LANL. The FORTRAN version is part of the SLATEC library of numerical analysis routines.

Steve Verrill translated the FORTRAN code (updated 6/18/92) into Java. This translation was performed on February 22, 2002.

Parameters:
x -

dcsevl

public static double dcsevl(double x,
                            double[] cs,
                            int n)
This method evaluates the n-term Chebyshev series cs at x. It is a Java translation of the FORTRAN routine dcsevl written by W. Fullerton of LANL. The FORTRAN version is part of the SLATEC library of numerical analysis routines.

Steve Verrill translated the FORTRAN code (updated 5/1/92) into Java. This translation was performed on February 22, 2002.

Parameters:
x - Value at which the series is to be evaluated
cs - Array of n terms of a Chebyshev series. In evaluating cs, only half the first coefficient is summed.
n - Number of terms in array cs (excludes the term in the 0th spot)

initds

public static int initds(double[] os,
                         int nos,
                         double eta)
This method determines the number of terms needed in an orthogonal polynomial series so that it meets a specified accuracy. It is a Java translation of the FORTRAN routine initds written by W. Fullerton of LANL. The FORTRAN version is part of the SLATEC library of numerical analysis routines.

Steve Verrill translated the FORTRAN code (updated 3/15/90) into Java. This translation was performed on February 22, 2002.

Parameters:
os - Double precision array of nos coefficients in an orthogonal series
nos - Number of coefficients in os
eta - Scalar containing the requested accuracy of the series

sign

public static double sign(double a,
                          double b)

This method implements the FORTRAN sign (not sin) function. See the code for details. Created by Steve Verrill, March 1997.

Parameters:
a - a
b - b