Package de.tilman_neumann.jml.transcendental

Class Agm

java.lang.Object

de.tilman_neumann.jml.transcendental.Agm

public class Agm
extends Object

Constructor Summary

Constructors

Constructor	Description
Agm()

Method Summary

Modifier and Type	Method	Description
static BigDecimal	agm(BigDecimal a, BigDecimal b, Scale outScale)	Arithmetic-geometric mean of a and b.
static int	getResultMagnitude(BigDecimal a, BigDecimal b)	Computes an estimate of the size of agm(a, b) in decimal digits.
static void	main(String[] args)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Agm

public Agm()

Method Detail

agm

public static BigDecimal agm(BigDecimal a,
                             BigDecimal b,
                             Scale outScale)

Arithmetic-geometric mean of a and b. The core is computed in BigIntegers, which is much faster than a BigDecimal-core. agm(a, b) will be pretty slow if |ln(|a/b|)| is large, because then the initial sqrt guess is not good enough.

Parameters:

a -

b -

outScale - desired precision in after-floating point digits

Returns:

agm(a, b)

getResultMagnitude

public static int getResultMagnitude(BigDecimal a,
                                     BigDecimal b)

Computes an estimate of the size of agm(a, b) in decimal digits.

Parameters:

a -

b -

Returns:

estimated magnitude of agm(a, b)

main

public static void main(String[] args)