Package it.unimi.dsi.law.big.util

Class ExchangeWeigher

java.lang.Object

it.unimi.dsi.law.big.util.ExchangeWeigher

public class ExchangeWeigher
extends Object

Computes the weight of discordances using a generalisation of Knight's algorithm.

Constructor Summary

Constructors

Constructor	Description
ExchangeWeigher(Long2DoubleFunction weigher, long[][] perm, double[][] v, long[][] rank, boolean multiplicative, long[][] support)	Creates a new exchange weigher.

Method Summary

Modifier and Type	Method	Description
double	weigh()	Computes the weight of exchanges for the current data.

Methods inherited from class java.lang.Object

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

Constructor Details

ExchangeWeigher

public ExchangeWeigher(Long2DoubleFunction weigher,
long[][] perm,
double[][] v,
long[][] rank,
boolean multiplicative,
long[][] support)

Creates a new exchange weigher.

Parameters:

weigher - the function used to weight indices.

perm - the big array to be sorted.

v - the score big vector used to compare the element of perm.

rank - a rank on the indices.

multiplicative - whether to combine weights multiplicatively, rather than additively, which is the default.

support - a big array that will be used as temporary storage during the computation; its content will be erased, and it must be at least as long as perm. If null, it will be allocated.

Method Details

weigh

public double weigh()

Computes the weight of exchanges for the current data.

Note that a call to this method will actually order the big array provided at creation time using the comparator provided at creation time; thus, subsequent calls will always return 1.

Returns:

the weight of exchanges that will order the vector provided at creation time using the comparator provided at creation time.