Vlib/graph.c File Reference

#include <stdlib.h>
#include <string.h>
#include <grass/gis.h>
#include <grass/dbmi.h>
#include <grass/Vect.h>

Include dependency graph for Vlib/graph.c:

Go to the source code of this file.

Functions
void	Vect_graph_init (GRAPH *graph, int nodes_costs)
	Build network graph. Internal format for edge costs is integer, costs are multiplied before conversion to int by 1000. Costs -1 for infinity i.e. arc or node is closed and cannot be traversed.
void	Vect_graph_build (GRAPH *graph)
void	Vect_graph_add_edge (GRAPH *graph, int from, int to, double costs, int id)
	Add edge to graph. Internal format for edge costs is integer, costs are multiplied before conversion to int by 1000. Costs -1 for infinity i.e. arc or node is closed and cannot be traversed.
void	Vect_graph_set_node_costs (GRAPH *graph, int node, double costs)
	Set node costs Internal format for edge costs is integer, costs are multiplied before conversion to int by 1000. Costs -1 for infinity i.e. arc or node is closed and cannot be traversed.
int	Vect_graph_shortest_path (GRAPH *graph, int from, int to, struct ilist *List, double *cost)
	Find shortest path. Costs for 'from' and 'to' nodes are not considered (SP found even if 'from' or 'to' are 'closed' (costs = -1) and costs of these nodes are not added to SP costs result.

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Function Documentation

Vect_graph_add_edge	(	GRAPH *	graph,
		int	from,
		int	to,
		double	costs,
		int	id
	)

Add edge to graph. Internal format for edge costs is integer, costs are multiplied before conversion to int by 1000. Costs -1 for infinity i.e. arc or node is closed and cannot be traversed.

Parameters:

	GRAPH	*graph
	from	from node
	to	to node
	costs
	id	edge id

Definition at line 111 of file Vlib/graph.c.

References dglAddEdge().

void Vect_graph_build

(

GRAPH *

graph

)

Definition at line 89 of file Vlib/graph.c.

References dglFlatten().

Vect_graph_init	(	GRAPH *	graph,
		int	nodes_costs
	)

Build network graph. Internal format for edge costs is integer, costs are multiplied before conversion to int by 1000. Costs -1 for infinity i.e. arc or node is closed and cannot be traversed.

Parameters:

	GRAPH	*graph
	nodes_costs	use node costs

Definition at line 68 of file Vlib/graph.c.

References dglInitialize().

Vect_graph_set_node_costs	(	GRAPH *	graph,
		int	node,
		double	costs
	)

Set node costs Internal format for edge costs is integer, costs are multiplied before conversion to int by 1000. Costs -1 for infinity i.e. arc or node is closed and cannot be traversed.

Parameters:

	GRAPH	*graph
	node
	costs

Definition at line 134 of file Vlib/graph.c.

References dglGetNode(), and dglNodeSet_Attr().

int Vect_graph_shortest_path	(	GRAPH *	graph,
		int	from,
		int	to,
		struct ilist *	List,
		double *	cost
	)

Find shortest path. Costs for 'from' and 'to' nodes are not considered (SP found even if 'from' or 'to' are 'closed' (costs = -1) and costs of these nodes are not added to SP costs result.

Returns:

number of segments : ( 0 is correct for from = to, or List == NULL ), ? sum of costs is better return value, -1 : destination unreachable

Parameters:

	graph
	from
	to
	List
	cost

Definition at line 160 of file Vlib/graph.c.

References _dglSPReport::cArc, dglEdgeGet_Cost(), dglEdgeGet_Id(), dglFreeSPReport(), dglShortestDistance(), dglShortestPath(), dglStrerror(), _dglSPReport::nDistance, _dglSPArc::nDistance, _dglSPArc::nFrom, _dglSPArc::nTo, _dglSPReport::pArc, _dglSPArc::pnEdge, Vect_list_append(), and Vect_reset_list().