Package com.jgalgo.graph

Class WeightFunctions

java.lang.Object

com.jgalgo.graph.WeightFunctions

public class WeightFunctions
extends Object

Static methods class for weight functions.

Author:

Barak Ugav

Method Summary

Modifier and Type	Method	Description
static IWeightFunction	asIntGraphWeightFunc(WeightFunction<Integer> w)	Treat a given weight function as a weight function on a graph with integer vertices.
static IWeightFunction	localEdgeWeightFunction(IndexGraph g, IWeightFunction w)	Get a 'local' version of a given weight function.
static IWeightFunctionInt	localEdgeWeightFunction(IndexGraph g, IWeightFunctionInt w)	Get a 'local' version of a given weight function.

Methods inherited from class java.lang.Object

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

Method Detail

localEdgeWeightFunction

public static IWeightFunction localEdgeWeightFunction(IndexGraph g,
                                                      IWeightFunction w)

Get a 'local' version of a given weight function.

A IWeightFunction is a functional interface, and may be implemented in many mays, and querying the weight of a single edge may be arbitrarily costly. In scenarios in which the weights of the edges are needed multiple times, it may be more efficient to query the weights of each edge once and store the result locally, to ensure the potentially heavy computations occur few as possible.

This method accept a weight function, and return a 'local' version of it. If the original weight function is already some 'local' implementation of a weight function, it will be returned as is without duplication. In other cases, in which the implementation decide to, the weights of the edges are computed onces and stored in a local weight function, which is than returned. In all cases, the returned weight function is local.

This function is used only for performance boost, it does not change any functionally over using the original weight function.

Parameters:

g - a graph

w - a weight function

Returns:

a local version of the weight function

localEdgeWeightFunction

public static IWeightFunctionInt localEdgeWeightFunction(IndexGraph g,
                                                         IWeightFunctionInt w)

Get a 'local' version of a given weight function.

A IWeightFunction is a functional interface, and may be implemented in many mays, and querying the weight of a single edge may be arbitrarily costly. In scenarios in which the weights of the edges are needed multiple times, it may be more efficient to query the weights of each edge once and store the result locally, to ensure the potentially heavy computations occur few as possible.

This method accept a weight function, and return a 'local' version of it. If the original weight function is already some 'local' implementation of a weight function, it will be returned as is without duplication. In other cases, in which the implementation decide to, the weights of the edges are computed onces and stored in a local weight function, which is than returned. In all cases, the returned weight function is local.

This function is used only for performance boost, it does not change any functionally over using the original weight function.

Parameters:

g - a graph

w - a weight function

Returns:

a local version of the weight function

asIntGraphWeightFunc

public static IWeightFunction asIntGraphWeightFunc(WeightFunction<Integer> w)

Treat a given weight function as a weight function on a graph with integer vertices.

Parameters:

w - a weight function

Returns:

a weight function on a graph with integer vertices