org.neo4j.graphalgo

Interface CostEvaluator<T>

Type Parameters:

T - The data type the edge weights are represented by.

public interface CostEvaluator<T>

In order to make the solving of shortest path problems as general as possible, the algorithms accept objects handling all relevant tasks regarding costs of paths. This allows the user to represent the costs in any possible way, and to calculate them in any way. The usual case is numbers that we just add together, but what if we have for example factors we would like to multiply instead? This is handled by this system, which works as follows. A CostEvaluator is used to get the cost for a single relationship. These costs are then added through a CostAccumulator. Costs for alternative paths are compared with a common java.util.Comparator.

Author:

Patrik Larsson

Method Summary

Modifier and Type	Method and Description
T	getCost(org.neo4j.graphdb.Relationship relationship, org.neo4j.graphdb.Direction direction) This is the general method for looking up costs for relationships.

Method Detail

getCost

T getCost(org.neo4j.graphdb.Relationship relationship,
          org.neo4j.graphdb.Direction direction)

This is the general method for looking up costs for relationships. This can do anything, like looking up a property or running some small calculation.

Parameters:

relationship - the relationship to get the cost for

direction - The direction in which the relationship is being evaluated, either Direction.INCOMING or Direction.OUTGOING.

Returns:

The cost for this edge/relationship