de.labathome

Class PreciseSummation

java.lang.Object

de.labathome.PreciseSummation

public class PreciseSummation
extends Object

Precise summation of many finite-relative-accuracy numbers of many different orders of magnitude

Author:

Jonathan Schilling (jonathan.schilling@ipp.mpg.de)

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	_debug Set this to true to get some debugging messages.

Constructor Summary

Constructors

Constructor and Description
PreciseSummation()

Method Summary

Modifier and Type	Method and Description
static double	preciseSum(double[] x) Returns the precise sum of all elements of x.

Methods inherited from class java.lang.Object

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

Field Detail

_debug

public static boolean _debug

Set this to true to get some debugging messages.

Constructor Detail

PreciseSummation

public PreciseSummation()

Method Detail

preciseSum

public static double preciseSum(double[] x)

Returns the precise sum of all elements of x. The values in x are put into a priority queue (min heap). Then, the two smallest numbers are drawn from the heap, added together and put back into the heap until the only element left in the heap is the sum of all elements of x.

Parameters:

x - [N] input array

Returns:

\sum_{i=0}^N x_i