GRASS GIS 7 Programmer's Manual
7.9.dev(2021)-e5379bbd7
|
Vector library - graph manipulation. More...
#include <stdlib.h>
#include <string.h>
#include <grass/dbmi.h>
#include <grass/vector.h>
#include <grass/glocale.h>
Go to the source code of this file.
Functions | |
void | Vect_graph_init (dglGraph_s *graph, int nodes_costs) |
Initialize graph structure. More... | |
void | Vect_graph_build (dglGraph_s *graph) |
Build network graph. More... | |
void | Vect_graph_add_edge (dglGraph_s *graph, int from, int to, double costs, int id) |
Add edge to graph. More... | |
void | Vect_graph_set_node_costs (dglGraph_s *graph, int node, double costs) |
Set node costs. More... | |
int | Vect_graph_shortest_path (dglGraph_s *graph, int from, int to, struct ilist *List, double *cost) |
Find shortest path. More... | |
Vector library - graph manipulation.
Higher level functions for reading/writing/manipulating vectors.
(C) 2001-2009 by 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.
Definition in file vector/Vlib/graph.c.
void Vect_graph_add_edge | ( | dglGraph_s * | 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.
graph | pointer to graph structure |
from | from node |
to | to node |
costs | costs value |
id | edge id |
Definition at line 124 of file vector/Vlib/graph.c.
References _, dglAddEdge(), G_debug(), and G_fatal_error().
void Vect_graph_build | ( | dglGraph_s * | graph | ) |
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.
graph | pointer to graph structure |
Definition at line 97 of file vector/Vlib/graph.c.
References _, dglFlatten(), G_debug(), and G_fatal_error().
void Vect_graph_init | ( | dglGraph_s * | graph, |
int | nodes_costs | ||
) |
Initialize graph structure.
graph | pointer to graph structure |
nodes_costs | use node costs |
Definition at line 71 of file vector/Vlib/graph.c.
References dglInitialize(), and G_debug().
void Vect_graph_set_node_costs | ( | dglGraph_s * | 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.
graph | pointer to graph structure |
node | node id |
costs | costs value |
Definition at line 154 of file vector/Vlib/graph.c.
References dglGetNode(), dglNodeSet_Attr(), and G_debug().
int Vect_graph_shortest_path | ( | dglGraph_s * | 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.
graph | pointer to graph structure |
from | from node |
to | to node |
List | list of line ids |
cost | costs value |
Definition at line 184 of file vector/Vlib/graph.c.