sparksee.SinglePairShortestPathDijkstra Class Reference

SinglePairShortestPathDijkstra class. More...

Inheritance diagram for sparksee.SinglePairShortestPathDijkstra:

Collaboration diagram for sparksee.SinglePairShortestPathDijkstra:

Public Member Functions
def	__init__ (self, session, src, dst)
	Creates a new instance. More...
def	exclude_nodes (self, nodes)
	Set which nodes can't be used. More...
def	get_cost (self)
	Gets the cost of the shortest path. More...
def	run (self)
	Executes the algorithm.
def	add_all_edge_types (self, dir)
	Allows for traversing all edge types of the graph. More...
def	exclude_edges (self, edges)
	Set which edges can't be used. More...
def	add_edge_type (self, type, dir)
	Allows for traversing edges of the given type. More...
def	set_unweighted_edge_cost (self, weight)
	Sets the weight assigned to the unweighted edges. More...
def	get_path_as_nodes (self)
	Gets the shortest path between the source node and the destination node as an ordered set of nodes. More...
def	set_dynamic_edge_cost_callback (self, dyn_cost_calculator)
	Set a class callback to dynamically calculate the cost of the edges. More...
def	add_node_type (self, type)
	Allows for traversing nodes of the given type. More...
def	exists (self)
	Returns TRUE If a path exists or FALSE otherwise.
def	get_path_as_edges (self)
	Gets the shortest path between the source node and the destination node as an ordered set of edges. More...
def	add_weighted_edge_type (self, type, dir, attr)
	Allows for traversing edges of the given type using the given attribute as the weight. More...
def	set_maximum_hops (self, maxhops)
	Sets the maximum hops restriction. More...
def	add_all_node_types (self)
	Allows for traversing all node types of the graph.
def	close (self)
	Closes the ShortestPath instance. More...
def	is_closed (self)
	Gets if ShortestPath has been closed or not. More...

Detailed Description

SinglePairShortestPathDijkstra class.

It solves the single-pair shortest path problem using a Dijkstra-based implementation.

It is a weighted algorithm, so it takes into account the cost of the edges to compute a minimum-cost shortest path. That is, the user may set for each edge type which attribute should be used to retrieve the cost of the edge. If no attribute is given for an edge type, this will assume the edge has a fixed cost (the default is 1). Only numerical attribute can be set as weight attributes (that is Long, Integer or Double attributes are allowed).

Check out the 'Algorithms' section in the SPARKSEE User Manual for more details on this.

Author

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

Constructor & Destructor Documentation

def sparksee.SinglePairShortestPathDijkstra.__init__	(		self,
			session,
			src,
			dst
	)

Creates a new instance.

Parameters

session	[in] Session to get the graph from and perform traversal.
src	[in] Source node.
dst	[dst] Destination node.

Member Function Documentation

def sparksee.SinglePairShortestPathDijkstra.add_all_edge_types	(		self,
			dir
	)

Allows for traversing all edge types of the graph.

Parameters

dir	[in] Edge direction.

def sparksee.SinglePairShortestPathDijkstra.add_edge_type	(		self,
			type,
			dir
	)

Allows for traversing edges of the given type.

Parameters

type	[in] Edge type.
dir	[in] Edge direction.

def sparksee.SinglePairShortestPathDijkstra.add_node_type	(		self,
			type
	)

Allows for traversing nodes of the given type.

Parameters

type

null

def sparksee.SinglePairShortestPathDijkstra.add_weighted_edge_type	(		self,
			type,
			dir,
			attr
	)

Allows for traversing edges of the given type using the given attribute as the weight.

Parameters

type	[in] Edge type.
dir	[in] Edge direction.
attr	[in] Attribute to be used as the weight. It must be a global attribute or an attribute of the given edge type.

def sparksee.ShortestPath.close (   self )

inherited

Closes the ShortestPath instance.

It must be called to ensure the integrity of all data.

def sparksee.SinglePairShortestPathDijkstra.exclude_edges	(		self,
			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.

Parameters

edges

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

def sparksee.SinglePairShortestPathDijkstra.exclude_nodes	(		self,
			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.

Parameters

nodes

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

def sparksee.SinglePairShortestPathDijkstra.get_cost

(

self

)

Gets the cost of the shortest path.

The cost is the sum of the weights of the edges in the shortest path.

Returns

The cost of the shortest path.

def sparksee.SinglePairShortestPathDijkstra.get_path_as_edges

(

self

)

Gets the shortest path between the source node and the destination node as an ordered set of edges.

Returns

Ordered set of edge identifiers.

def sparksee.SinglePairShortestPathDijkstra.get_path_as_nodes

(

self

)

Gets the shortest path between the source node and the destination node as an ordered set of nodes.

Returns

Ordered set of node identifiers.

def sparksee.ShortestPath.is_closed (   self )

inherited

Gets if ShortestPath has been closed or not.

See also

close()

Returns

TRUE if the ShortestPath instance has been closed, FALSE otherwise.

def sparksee.SinglePairShortestPathDijkstra.set_dynamic_edge_cost_callback	(		self,
			dyn_cost_calculator
	)

Set a class callback to dynamically calculate the cost of the edges.

The callback can be set to NULL (the default) to use the normal attribute based cost weights. The given class must be kept alive by the user for as long as the algorithm is running.

Parameters

dyn_cost_calculator

[in] Class callback to calculate the edge costs

def sparksee.SinglePairShortestPathDijkstra.set_maximum_hops	(		self,
			maxhops
	)

Sets the maximum hops restriction.

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

Parameters

maxhops

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

def sparksee.SinglePairShortestPathDijkstra.set_unweighted_edge_cost	(		self,
			weight
	)

Sets the weight assigned to the unweighted edges.

All the edges from the types added without an explicit weight attribute will get this weight. The default weight for this edges is 1.

Parameters

weight

[in] The weight value for unweighted edges.