com.sparsity.sparksee.algorithms

Class RandomWalk

java.lang.Object

com.sparsity.sparksee.algorithms.Traversal

com.sparsity.sparksee.algorithms.RandomWalk

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class RandomWalk
extends Traversal

RandomWalk class.

Implements the RandomWalk algorithm

Author:

Sparsity Technologies http://www.sparsity-technologies.com

Constructor Summary

Constructors

Constructor and Description
RandomWalk(Session session, long node) Builds the RandomWalk.

Method Summary

Modifier and Type	Method and Description
void	addAllEdgeTypes(EdgesDirection dir) Allows for traversing all edge types of the graph.
void	addAllNodeTypes() Allows for traversing all node types of the graph.
void	addEdgeType(int type, EdgesDirection dir) Allows for traversing edges of the given type.
void	addNodeType(int type) Allows for traversing nodes of the given type.
void	excludeEdges(Objects edges) Set which edges can't be used.
void	excludeNodes(Objects nodes) Set which nodes can't be used.
int	getCurrentDepth() Returns the depth of the current node.
boolean	hasNext() Gets if there are more objects to be traversed.
long	next() Gets the next object of the traversal.
void	reset(long startNode) Sets the starting node of the RandomWalk.
void	setDefaultWeight(double weight) Sets the default weight for those cases when a given edge does not have a weight attribute set.
void	setEdgeWeightAttributeType(int attr) Sets the attribute to use as edge weight.
void	setInOutParameter(double val) Sets the In-Out parameter of the RandomWalk.
void	setMaximumHops(int maxhops) Sets the maximum hops restriction.
void	setReturnParameter(double val) Sets the return parameter of the RandomWalk.
void	setSeed(int seed) Sets the seed of the random walk.

Methods inherited from class com.sparsity.sparksee.algorithms.Traversal

close, isClosed

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomWalk

public RandomWalk(Session session,
                  long node)

Builds the RandomWalk.

Parameters:

session - [in] The session to use

node - [in] The starting node of the traversal

Method Detail

excludeNodes

public void excludeNodes(Objects nodes)

Set which nodes can't be used.

This will replace any previously specified set of excluded nodes. Should only be used to exclude the usage of specific nodes from allowed node types because it's less efficient than not allowing a node type.

Overrides:

excludeNodes in class Traversal

Parameters:

nodes - [in] A set of node identifiers that must be kept intact until the destruction of the class.

setDefaultWeight

public void setDefaultWeight(double weight)

Sets the default weight for those cases when a given edge does not have a weight attribute set.

Default: 0.0

Parameters:

weight - [in] The default weight

addAllEdgeTypes

public void addAllEdgeTypes(EdgesDirection dir)

Allows for traversing all edge types of the graph.

Overrides:

addAllEdgeTypes in class Traversal

Parameters:

dir - [in] Edge direction.

excludeEdges

public void excludeEdges(Objects edges)

Set which edges can't be used.

This will replace any previously specified set of excluded edges. Should only be used to exclude the usage of specific edges from allowed edge types because it's less efficient than not allowing an edge type.

Overrides:

excludeEdges in class Traversal

Parameters:

edges - [in] A set of edge identifiers that must be kept intact until the destruction of the class.

setSeed

public void setSeed(int seed)

Sets the seed of the random walk.

Parameters:

seed - The seed to generate the random numbers that drive the random walk

setEdgeWeightAttributeType

public void setEdgeWeightAttributeType(int attr)

Sets the attribute to use as edge weight.

If the multiple edge are set for traversal, this attribute must be of type GLOBAL_TYPE or EDGES_TYPE. Additionally, the attribute must be of type Double. Finally, negative weights are treated as non existing, so the default weight applies.

Parameters:

attr - [in] The attribute type to use as a weight. Default: InvalidAttribute

setInOutParameter

public void setInOutParameter(double val)

Sets the In-Out parameter of the RandomWalk.

Parameters:

val - The In-Out parameter to set. Default: 1.0

addEdgeType

public void addEdgeType(int type,
                        EdgesDirection dir)

Allows for traversing edges of the given type.

If the edge type was already added, the existing direction is overwritten

Overrides:

addEdgeType in class Traversal

Parameters:

type - [in] Edge type.

dir - [in] Edge direction.

addNodeType

public void addNodeType(int type)

Allows for traversing nodes of the given type.

Overrides:

addNodeType in class Traversal

Parameters:

type - The node type to add

setReturnParameter

public void setReturnParameter(double val)

Sets the return parameter of the RandomWalk.

Parameters:

val - The return parameter to set. Default: 1.0

next

public long next()

Gets the next object of the traversal.

Overrides:

next in class Traversal

Returns:

A node or edge identifier.

hasNext

public boolean hasNext()

Gets if there are more objects to be traversed.

Overrides:

hasNext in class Traversal

Returns:

TRUE if there are more objects, FALSE otherwise.

getCurrentDepth

public int getCurrentDepth()

Returns the depth of the current node.

That is, it returns the depth of the node returned in the last call to Next().

Overrides:

getCurrentDepth in class Traversal

Returns:

The depth of the current node.

reset

public void reset(long startNode)

Sets the starting node of the RandomWalk.

This method resets the RandomWalk.

sparksee::gdb::Error

Parameters:

startNode - null

addAllNodeTypes

public void addAllNodeTypes()

Allows for traversing all node types of the graph.

Overrides:

addAllNodeTypes in class Traversal

setMaximumHops

public void setMaximumHops(int maxhops)

Sets the maximum hops restriction.

All paths longer than the maximum hops restriction will be ignored.

Overrides:

setMaximumHops in class Traversal

Parameters:

maxhops - [in] The maximum hops restriction. It must be positive or zero. Zero, the default value, means unlimited.