Vector library - net releated fns. More...

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

Include dependency graph for net.c:

Go to the source code of this file.

Functions
int	Vect_net_build_graph (struct Map_info Map, int ltype, int afield, int nfield, const char afcol, const char abcol, const char ncol, int geo, int algorithm)
	Build network graph. More...

int	Vect_net_shortest_path (struct Map_info Map, int from, int to, struct ilist List, double *cost)
	Find shortest path. More...

int	Vect_net_get_line_cost (struct Map_info Map, int line, int direction, double cost)
	Returns in cost for given direction in *cost. More...

int	Vect_net_get_node_cost (struct Map_info Map, int node, double cost)
	Get cost of node. More...

int	Vect_net_nearest_nodes (struct Map_info Map, double x, double y, double z, int direction, double maxdist, int node1, int node2, int ln, double costs1, double costs2, struct line_pnts Points1, struct line_pnts Points2, double *distance)
	Find nearest node(s) on network. More...

int	Vect_net_shortest_path_coor (struct Map_info Map, double fx, double fy, double fz, double tx, double ty, double tz, double fmax, double tmax, double costs, struct line_pnts Points, struct ilist List, struct line_pnts FPoints, struct line_pnts TPoints, double fdist, double tdist)
	Find shortest path on network between 2 points given by coordinates. More...

int	Vect_net_shortest_path_coor2 (struct Map_info Map, double fx, double fy, double fz, double tx, double ty, double tz, double fmax, double tmax, double costs, struct line_pnts Points, struct ilist List, struct ilist NodesList, struct line_pnts FPoints, struct line_pnts TPoints, double fdist, double *tdist)
	Find shortest path on network between 2 points given by coordinates. More...

Detailed Description

Vector library - net releated fns.

Higher level functions for reading/writing/manipulating vectors.

This program is free software under the GNU General Public License (>=v2). Read the file COPYING that comes with GRASS for details.

Author: Radim Blazek

Date: 2001-2008

Definition in file net.c.

Function Documentation

int Vect_net_build_graph	(	struct Map_info *	Map,
		int	ltype,
		int	afield,
		int	nfield,
		const char *	afcol,
		const char *	abcol,
		const char *	ncol,
		int	geo,
		int	algorithm
	)

Build network graph.

Internal format for edge costs is integer, costs are multiplied before conversion to int by 1000 and for lenghts LL without geo flag by 1000000. The same multiplication factor is used for nodes. Costs in database column may be 'integer' or 'double precision' number >= 0 or -1 for infinity i.e. arc or node is closed and cannot be traversed If record in table is not found for arcs, arc is skip. If record in table is not found for node, costs for node are set to 0.

Parameters

Map	vector map
ltype	line type for arcs
afield	arc costs field (if 0, use length)
nfield	node costs field (if 0, do not use node costs)
afcol	column with forward costs for arc
abcol	column with backward costs for arc (if NULL, back costs = forward costs),
ncol	column with costs for nodes (if NULL, do not use node costs),
geo	use geodesic calculation for length (LL),
algorithm	not used (in future code for algorithm)

Returns: 0 on success, 1 on error

Definition at line 91 of file net.c.

References cat, db_CatValArray_free(), db_CatValArray_get_value_double(), db_CatValArray_get_value_int(), db_CatValArray_init(), db_close_database_shutdown_driver(), db_get_column(), db_get_column_sqltype(), db_init_handle(), db_init_string(), db_select_CatValArray(), db_sqltype_to_Ctype(), db_start_driver_open_database(), dglAddEdge(), dglFlatten(), dglGetNode(), dglInitialize(), dglInitializeSPCache(), dglNodeSet_Attr(), G_debug(), G_fatal_error(), G_message(), G_percent(), G_projection(), G_warning(), NULL, dialogs::type, Vect_cat_get(), Vect_get_field(), Vect_get_line_nodes(), Vect_get_node_line(), Vect_get_node_n_lines(), Vect_get_num_lines(), Vect_get_num_nodes(), Vect_line_geodesic_length(), Vect_line_length(), Vect_new_cats_struct(), Vect_new_line_struct(), and Vect_read_line().

int Vect_net_get_line_cost	(	struct Map_info *	Map,
		int	line,
		int	direction,
		double *	cost
	)

Returns in cost for given direction in *cost.

cost is set to -1 if closed.

Parameters

Map	vector map
line	line id
direction	direction (GV_FORWARD, GV_BACKWARD)

Returns: 1 OK; 0 does not exist (was not inserted)

Definition at line 565 of file net.c.

References G_debug(), and G_fatal_error().

Referenced by Vect_net_nearest_nodes(), and Vect_net_shortest_path_coor2().

int Vect_net_get_node_cost	(	struct Map_info *	Map,
		int	node,
		double *	cost
	)

Get cost of node.

Parameters

	Map	vector map
	node	node id
[out]	cost	costs value

Returns: 1

Definition at line 618 of file net.c.

References G_debug().

int Vect_net_nearest_nodes	(	struct Map_info *	Map,
		double	x,
		double	y,
		double	z,
		int	direction,
		double	maxdist,
		int *	node1,
		int *	node2,
		int *	ln,
		double *	costs1,
		double *	costs2,
		struct line_pnts *	Points1,
		struct line_pnts *	Points2,
		double *	distance
	)

Find nearest node(s) on network.

Parameters

Map	vetor map
x,y,z	point coordinates (z coordinate NOT USED !)
direction	(GV_FORWARD - from point to net, GV_BACKWARD - from net to point)
maxdist	maximum distance to the network
node1	pointer where to store the node number (or NULL)
node2	pointer where to store the node number (or NULL)
ln	pointer where to store the nearest line number (or NULL)
costs1	pointer where to store costs on nearest line to node1 (not costs from x,y,z to the line) (or NULL)
costs2	pointer where to store costs on nearest line to node2 (not costs from x,y,z to the line) (or NULL)
Points1	pointer to structure where to store vertices on nearest line to node1 (or NULL)
Points2	pointer to structure where to store vertices on nearest line to node2 (or NULL)
pointer	where to distance to the line (or NULL)

Returns: number of nodes found (0,1,2)

Definition at line 647 of file net.c.

References G_debug(), NULL, Vect_append_point(), Vect_find_line(), Vect_get_line_nodes(), Vect_line_distance(), Vect_line_length(), Vect_net_get_line_cost(), Vect_new_line_struct(), Vect_read_line(), and Vect_reset_line().

Referenced by Vect_net_shortest_path_coor2().

int Vect_net_shortest_path	(	struct Map_info *	Map,
		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.

Parameters

	Map	vector map
	from	from node
	to	to node
[out]	List	list of line ids (path)
[out]	cost	costs value

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

Definition at line 464 of file net.c.

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

Referenced by Vect_net_shortest_path_coor2().

int Vect_net_shortest_path_coor	(	struct Map_info *	Map,
		double	fx,
		double	fy,
		double	fz,
		double	tx,
		double	ty,
		double	tz,
		double	fmax,
		double	tmax,
		double *	costs,
		struct line_pnts *	Points,
		struct ilist *	List,
		struct line_pnts *	FPoints,
		struct line_pnts *	TPoints,
		double *	fdist,
		double *	tdist
	)

Find shortest path on network between 2 points given by coordinates.

Parameters

Map	vector map
fx,fy,fz	from point x coordinate (z ignored)
tx,ty,tz	to point x coordinate (z ignored)
fmax	maximum distance to the network from 'from'
tmax	maximum distance to the network from 'to'
costs	pointer where to store costs on the network (or NULL)
Points	pointer to the structure where to store vertices of shortest path (or NULL)
List	pointer to the structure where list of lines on the network is stored (or NULL)
FPoints	pointer to the structure where to store line from 'from' to first network node (or NULL)
TPoints	pointer to the structure where to store line from last network node to 'to' (or NULL)
fdist	distance from 'from' to the net (or NULL)
tdist	distance from 'to' to the net (or NULL)

Returns: 1 OK, 0 not reachable

Definition at line 866 of file net.c.

References NULL, and Vect_net_shortest_path_coor2().

int Vect_net_shortest_path_coor2	(	struct Map_info *	Map,
		double	fx,
		double	fy,
		double	fz,
		double	tx,
		double	ty,
		double	tz,
		double	fmax,
		double	tmax,
		double *	costs,
		struct line_pnts *	Points,
		struct ilist *	List,
		struct ilist *	NodesList,
		struct line_pnts *	FPoints,
		struct line_pnts *	TPoints,
		double *	fdist,
		double *	tdist
	)

Find shortest path on network between 2 points given by coordinates.

Parameters

Map	vector map
fx,fy,fz	from point x coordinate (z ignored)
tx,ty,tz	to point x coordinate (z ignored)
fmax	maximum distance to the network from 'from'
tmax	maximum distance to the network from 'to'
costs	pointer where to store costs on the network (or NULL)
Points	pointer to the structure where to store vertices of shortest path (or NULL)
List	pointer to the structure where list of lines on the network is stored (or NULL)
List	pointer to the structure where list of nodes on the network is stored (or NULL)
FPoints	pointer to the structure where to store line from 'from' to first network node (or NULL)
TPoints	pointer to the structure where to store line from last network node to 'to' (or NULL)
fdist	distance from 'from' to the net (or NULL)
tdist	distance from 'to' to the net (or NULL)

Returns: 1 OK, 0 not reachable

Definition at line 898 of file net.c.

References first, frame::fn, G_debug(), NULL, Vect_append_point(), Vect_append_points(), Vect_get_line_nodes(), Vect_line_distance(), Vect_line_length(), Vect_list_append(), Vect_net_get_line_cost(), Vect_net_nearest_nodes(), Vect_net_shortest_path(), Vect_new_line_struct(), Vect_new_list(), Vect_read_line(), Vect_reset_line(), and Vect_reset_list().

Referenced by Vect_net_shortest_path_coor().

Functions

Detailed Description

Function Documentation