timetables.c File Reference

Network Analysis library - timetables. More...

#include <stdio.h>
#include <stdlib.h>
#include <grass/gis.h>
#include <grass/vector.h>
#include <grass/dbmi.h>
#include <grass/glocale.h>
#include <grass/dgl/graph.h>
#include <grass/neta.h>

Include dependency graph for timetables.c:

Go to the source code of this file.

Functions
int	NetA_init_distinct (dbDriver *driver, dbString *sql, int **lengths, int **ids)
	Get number of distinct elements. More...
int	NetA_init_timetable_from_db (struct Map_info *In, int route_layer, int walk_layer, char *route_id, char *times, char *to_stop, char *walk_length, neta_timetable *timetable, int **route_ids, int **stop_ids)
	Initialises timetable from a database. More...
void	NetA_update_dijkstra (int old_conns, int new_conns, int to, int new_dst, int v, int route, int rows UNUSED, int update, neta_timetable_result *result, dglHeap_s *heap)
	Update Dijkstra structures. More...
int	NetA_timetable_shortest_path (neta_timetable *timetable, int from_stop, int to_stop, int start_time, int min_change, int max_changes, int walking_change, neta_timetable_result *result)
	Computes the earliest arrival time. More...
int	NetA_timetable_get_route_time (neta_timetable *timetable, int stop, int route)
	Get time. More...
void	NetA_timetable_result_release (neta_timetable_result *result)
	Free neta_timetable_result structure. More...

Detailed Description

Network Analysis library - timetables.

Shortest path using timetables.

(C) 2009-2010 by Daniel Bundala, and the GRASS Development Team

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

Author

Daniel Bundala (Google Summer of Code 2009)

Definition in file timetables.c.

Function Documentation

NetA_init_distinct()

int NetA_init_distinct	(	dbDriver *	driver,
		dbString *	sql,
		int **	lengths,
		int **	ids
	)

Get number of distinct elements.

Parameters

	driver	DB driver
	sql	SQl string
[out]	list	of lengths
[out]	list	of ids

Returns

number of distinct elements

-1 on failure

Definition at line 36 of file timetables.c.

References count.

NetA_init_timetable_from_db()

int NetA_init_timetable_from_db	(	struct Map_info *	In,
		int	route_layer,
		int	walk_layer,
		char *	route_id,
		char *	times,
		char *	to_stop,
		char *	walk_length,
		neta_timetable *	timetable,
		int **	route_ids,
		int **	stop_ids
	)

Initialises timetable from a database.

Parameters

In	pointer to Map_info structure
route_layer	layer number of routes
walk_layer	layer number of walkers
route_id	id of route
times	list of timestamps
to_stop	?
walk_length	walk length as string
timetable	pointer to neta_timetable
route_ids	list of route ids
stop_ids	list of stop ids

Returns

0 on success

non-zero value on failure

Definition at line 116 of file timetables.c.

NetA_timetable_get_route_time()

int NetA_timetable_get_route_time	(	neta_timetable *	timetable,
		int	stop,
		int	route
	)

Get time.

Get time when route "route" arrives at stop "stop" or -1.

Parameters

timetable	pointer to neta_timetable structure
stop	'stop' node id
route	route id

Returns

time

-1 if not found

Definition at line 530 of file timetables.c.

References neta_timetable::route_length, neta_timetable::route_stops, and neta_timetable::route_times.

NetA_timetable_result_release()

void NetA_timetable_result_release

(

neta_timetable_result *

result

)

Free neta_timetable_result structure.

Parameters

result

pointer to neta_timetable_result structure

Definition at line 546 of file timetables.c.

References neta_timetable_result::dst, G_free(), neta_timetable_result::prev_route, neta_timetable_result::prev_stop, and neta_timetable_result::rows.

NetA_timetable_shortest_path()

int NetA_timetable_shortest_path	(	neta_timetable *	timetable,
		int	from_stop,
		int	to_stop,
		int	start_time,
		int	min_change,
		int	max_changes,
		int	walking_change,
		neta_timetable_result *	result
	)

Computes the earliest arrival time.

Computes the earliest arrival time to to_stop from from_stop starting at start_time, or -1 if no path exists

Parameters

	timetable	pointer to neta_timetable structure
	from_stop	'from' node
	to_stop	'to' stop
	start_time	start timestamp
	min_change	?
	max_changes	?
	walking_change	?
[out]	result	pointer to neta_timetable_result

Returns

?

-1 on error

Definition at line 388 of file timetables.c.

References _, dglHeapInit(), neta_timetable_result::dst, G_calloc, G_warning(), neta_timetable_result::prev_conn, neta_timetable_result::prev_route, neta_timetable_result::prev_stop, _dglHeapData::pv, neta_timetable_result::routes, neta_timetable_result::rows, and neta_timetable::stops.

NetA_update_dijkstra()

void NetA_update_dijkstra	(	int	old_conns,
		int	new_conns,
		int	to,
		int	new_dst,
		int	v,
		int	route,
		int rows	UNUSED,
		int	update,
		neta_timetable_result *	result,
		dglHeap_s *	heap
	)

Update Dijkstra structures.

Parameters

	olc_conns	old connection
	new_conns	new connection
	to	old 'to' node
	new_dst	new 'to' node
	v	?
	route	id of route
	rows	? (unused)
	update	?
[out]	result	pointer to neta_timetable_result structure
	heap	?

Definition at line 351 of file timetables.c.

References neta_timetable_result::dst, neta_timetable_result::prev_conn, neta_timetable_result::prev_route, neta_timetable_result::prev_stop, and _dglHeapData::pv.