/*!
\brief Find a path (minimum number of edges) from 'from' to 'to' using only edges in 'edges'.
Precisely, edge with id I is used if edges[abs(i)] == 1. List
stores the indices of lines on the path. Method return number of
edges or -1 if no path exist.
\param graph input graph
\param from 'from' position
\param to 'to' position
\param edges list of available edges
\param[out] list list of edges
\return number of edges
\return -1 on failure
*/
int NetA_find_path(dglGraph_s * graph, int from, int to, int *edges,
struct ilist *list)
{
dglInt32_t **prev, *queue;
dglEdgesetTraverser_s et;
char *vis;
int begin, end, cur, nnodes;
nnodes = dglGet_NodeCount(graph);
prev = (dglInt32_t **) G_calloc(nnodes + 1, sizeof(dglInt32_t *));
queue = (dglInt32_t *) G_calloc(nnodes + 1, sizeof(dglInt32_t));
vis = (char *)G_calloc(nnodes + 1, sizeof(char));
if (!prev || !queue || !vis) {
G_fatal_error(_("Out of memory"));
return -1;
}
Vect_reset_list(list);
begin = 0;
end = 1;
vis[from] = 'y';
queue[0] = from;
prev[from] = NULL;
while (begin != end) {
dglInt32_t vertex = queue[begin++];
if (vertex == to)
break;
dglInt32_t *edge, *node = dglGetNode(graph, vertex);
dglEdgeset_T_Initialize(&et, graph,
dglNodeGet_OutEdgeset(graph, node));
for (edge = dglEdgeset_T_First(&et); edge;
edge = dglEdgeset_T_Next(&et)) {
dglInt32_t id = abs(dglEdgeGet_Id(graph, edge));
dglInt32_t to =
dglNodeGet_Id(graph, dglEdgeGet_Tail(graph, edge));
if (edges[id] && !vis[to]) {
vis[to] = 'y';
prev[to] = edge;
queue[end++] = to;
}
}
dglEdgeset_T_Release(&et);
}
G_free(queue);
if (!vis[to]) {
G_free(prev);
G_free(vis);
return -1;
}
cur = to;
while (prev[cur] != NULL) {
Vect_list_append(list, abs(dglEdgeGet_Id(graph, prev[cur])));
cur = dglNodeGet_Id(graph, dglEdgeGet_Head(graph, prev[cur]));
}
G_free(prev);
G_free(vis);
return list->n_values;
}
/*!
\brief Computes weakly connected components
\param graph input graph
\param[out] component array of component ids
\return number of components
\return -1 on failure
*/
int NetA_weakly_connected_components(dglGraph_s * graph, int *component)
{
int nnodes, i;
dglInt32_t *stack;
int stack_size, components;
dglInt32_t *cur_node;
dglNodeTraverser_s nt;
int have_node_costs;
dglInt32_t ncost;
if (graph->Version < 2) {
G_warning("Directed graph must be version 2 or 3 for NetA_weakly_connected_components()");
return -1;
}
components = 0;
nnodes = dglGet_NodeCount(graph);
stack = (dglInt32_t *) G_calloc(nnodes + 1, sizeof(dglInt32_t));
if (!stack) {
G_fatal_error(_("Out of memory"));
return -1;
}
for (i = 1; i <= nnodes; i++)
component[i] = 0;
ncost = 0;
have_node_costs = dglGet_NodeAttrSize(graph);
dglNode_T_Initialize(&nt, graph);
for (cur_node = dglNode_T_First(&nt); cur_node;
cur_node = dglNode_T_Next(&nt)) {
dglInt32_t cur_node_id = dglNodeGet_Id(graph, cur_node);
if (!component[cur_node_id]) {
stack[0] = cur_node_id;
stack_size = 1;
component[cur_node_id] = ++components;
while (stack_size) {
dglInt32_t *node, *edgeset, *edge;
dglEdgesetTraverser_s et;
node = dglGetNode(graph, stack[--stack_size]);
edgeset = dglNodeGet_OutEdgeset(graph, node);
dglEdgeset_T_Initialize(&et, graph, edgeset);
for (edge = dglEdgeset_T_First(&et); edge;
edge = dglEdgeset_T_Next(&et)) {
dglInt32_t to;
to = dglNodeGet_Id(graph, dglEdgeGet_Tail(graph, edge));
if (!component[to]) {
component[to] = components;
/* do not go through closed nodes */
if (have_node_costs) {
memcpy(&ncost, dglNodeGet_Attr(graph, dglEdgeGet_Tail(graph, edge)),
sizeof(ncost));
}
if (ncost >= 0)
stack[stack_size++] = to;
}
}
dglEdgeset_T_Release(&et);
edgeset = dglNodeGet_InEdgeset(graph, node);
dglEdgeset_T_Initialize(&et, graph, edgeset);
for (edge = dglEdgeset_T_First(&et); edge;
edge = dglEdgeset_T_Next(&et)) {
dglInt32_t to;
to = dglNodeGet_Id(graph, dglEdgeGet_Head(graph, edge));
if (!component[to]) {
component[to] = components;
/* do not go through closed nodes */
if (have_node_costs) {
memcpy(&ncost, dglNodeGet_Attr(graph, dglEdgeGet_Tail(graph, edge)),
sizeof(ncost));
}
if (ncost >= 0)
stack[stack_size++] = to;
}
}
dglEdgeset_T_Release(&et);
}
}
}
dglNode_T_Release(&nt);
G_free(stack);
return components;
}
int main(int argc, char *argv[])
{
struct Map_info In, Out;
static struct line_pnts *Points;
struct line_cats *Cats, *TCats;
struct GModule *module; /* GRASS module for parsing arguments */
struct Option *map_in, *map_out;
struct Option *catf_opt, *fieldf_opt, *wheref_opt;
struct Option *catt_opt, *fieldt_opt, *wheret_opt, *typet_opt;
struct Option *afield_opt, *nfield_opt, *abcol, *afcol, *ncol, *atype_opt;
struct Flag *geo_f;
int with_z, geo;
int atype, ttype;
struct varray *varrayf, *varrayt;
int flayer, tlayer;
int afield, nfield;
dglGraph_s *graph;
struct ilist *nodest;
int i, nnodes, nlines;
int *dst, *nodes_to_features;
int from_nr; /* 'from' features not reachable */
dglInt32_t **prev;
struct line_cats **on_path;
char buf[2000];
/* Attribute table */
dbString sql;
dbDriver *driver;
struct field_info *Fi;
/* initialize GIS environment */
G_gisinit(argv[0]); /* reads grass env, stores program name to G_program_name() */
/* initialize module */
module = G_define_module();
G_add_keyword(_("vector"));
G_add_keyword(_("network"));
G_add_keyword(_("shortest path"));
module->label = _("Computes shortest distance via the network between "
"the given sets of features.");
module->description =
_("Finds the shortest paths from each 'from' point to the nearest 'to' feature "
"and various information about this relation are uploaded to the attribute table.");
/* Define the different options as defined in gis.h */
map_in = G_define_standard_option(G_OPT_V_INPUT);
map_out = G_define_standard_option(G_OPT_V_OUTPUT);
afield_opt = G_define_standard_option(G_OPT_V_FIELD);
afield_opt->key = "alayer";
afield_opt->answer = "1";
afield_opt->label = _("Arc layer");
afield_opt->guisection = _("Cost");
atype_opt = G_define_standard_option(G_OPT_V_TYPE);
atype_opt->options = "line,boundary";
atype_opt->answer = "line,boundary";
atype_opt->label = _("Arc type");
atype_opt->guisection = _("Cost");
nfield_opt = G_define_standard_option(G_OPT_V_FIELD);
nfield_opt->key = "nlayer";
nfield_opt->answer = "2";
nfield_opt->label = _("Node layer");
nfield_opt->guisection = _("Cost");
fieldf_opt = G_define_standard_option(G_OPT_V_FIELD);
fieldf_opt->key = "from_layer";
fieldf_opt->label = _("From layer number or name");
fieldf_opt->guisection = _("From");
catf_opt = G_define_standard_option(G_OPT_V_CATS);
catf_opt->key = "from_cats";
catf_opt->label = _("From category values");
catf_opt->guisection = _("From");
wheref_opt = G_define_standard_option(G_OPT_DB_WHERE);
wheref_opt->key = "from_where";
wheref_opt->label =
_("From WHERE conditions of SQL statement without 'where' keyword");
wheref_opt->guisection = _("From");
fieldt_opt = G_define_standard_option(G_OPT_V_FIELD);
fieldt_opt->key = "to_layer";
fieldt_opt->description = _("To layer number or name");
fieldt_opt->guisection = _("To");
typet_opt = G_define_standard_option(G_OPT_V_TYPE);
typet_opt->key = "to_type";
typet_opt->options = "point,line,boundary";
typet_opt->answer = "point";
typet_opt->description = _("To feature type");
typet_opt->guisection = _("To");
catt_opt = G_define_standard_option(G_OPT_V_CATS);
catt_opt->key = "to_cats";
catt_opt->label = _("To category values");
catt_opt->guisection = _("To");
wheret_opt = G_define_standard_option(G_OPT_DB_WHERE);
wheret_opt->key = "to_where";
wheret_opt->label =
_("To WHERE conditions of SQL statement without 'where' keyword");
wheret_opt->guisection = _("To");
afcol = G_define_standard_option(G_OPT_DB_COLUMN);
afcol->key = "afcolumn";
afcol->required = NO;
afcol->description =
_("Arc forward/both direction(s) cost column (number)");
afcol->guisection = _("Cost");
abcol = G_define_standard_option(G_OPT_DB_COLUMN);
abcol->key = "abcolumn";
abcol->required = NO;
abcol->description = _("Arc backward direction cost column (number)");
abcol->guisection = _("Cost");
ncol = G_define_standard_option(G_OPT_DB_COLUMN);
ncol->key = "ncolumn";
ncol->required = NO;
ncol->description = _("Node cost column (number)");
ncol->guisection = _("Cost");
geo_f = G_define_flag();
geo_f->key = 'g';
geo_f->description =
_("Use geodesic calculation for longitude-latitude locations");
/* options and flags parser */
if (G_parser(argc, argv))
exit(EXIT_FAILURE);
atype = Vect_option_to_types(atype_opt);
ttype = Vect_option_to_types(typet_opt);
Points = Vect_new_line_struct();
Cats = Vect_new_cats_struct();
TCats = Vect_new_cats_struct();
Vect_check_input_output_name(map_in->answer, map_out->answer,
G_FATAL_EXIT);
Vect_set_open_level(2);
if (1 > Vect_open_old(&In, map_in->answer, ""))
G_fatal_error(_("Unable to open vector map <%s>"), map_in->answer);
with_z = Vect_is_3d(&In);
if (0 > Vect_open_new(&Out, map_out->answer, with_z)) {
Vect_close(&In);
G_fatal_error(_("Unable to create vector map <%s>"), map_out->answer);
}
if (geo_f->answer) {
geo = 1;
if (G_projection() != PROJECTION_LL)
G_warning(_("The current projection is not longitude-latitude"));
}
else
geo = 0;
nnodes = Vect_get_num_nodes(&In);
nlines = Vect_get_num_lines(&In);
dst = (int *)G_calloc(nnodes + 1, sizeof(int));
prev = (dglInt32_t **) G_calloc(nnodes + 1, sizeof(dglInt32_t *));
nodes_to_features = (int *)G_calloc(nnodes + 1, sizeof(int));
on_path =
(struct line_cats **)G_calloc(nlines + 1, sizeof(struct line_cats *));
if (!dst || !prev || !nodes_to_features || !on_path)
G_fatal_error(_("Out of memory"));
for (i = 1; i <= nlines; i++)
on_path[i] = Vect_new_cats_struct();
/*initialise varrays and nodes list appropriatelly */
afield = Vect_get_field_number(&In, afield_opt->answer);
nfield = Vect_get_field_number(&In, nfield_opt->answer);
flayer = atoi(fieldf_opt->answer);
tlayer = atoi(fieldt_opt->answer);
if (NetA_initialise_varray(&In, flayer, GV_POINT, wheref_opt->answer,
catf_opt->answer, &varrayf) <= 0) {
G_fatal_error(_("No 'from' features selected. "
"Please check options '%s', '%s', '%s'."),
fieldf_opt->key, wheref_opt->key, catf_opt->key);
}
if (NetA_initialise_varray(&In, tlayer, ttype, wheret_opt->answer,
catt_opt->answer, &varrayt) <= 0) {
G_fatal_error(_("No 'to' features selected. "
"Please check options '%s', '%s', '%s'."),
fieldt_opt->key, wheret_opt->key, catt_opt->key);
}
nodest = Vect_new_list();
NetA_varray_to_nodes(&In, varrayt, nodest, nodes_to_features);
if (nodest->n_values == 0)
G_fatal_error(_("No 'to' features"));
if (0 != Vect_net_build_graph(&In, atype, afield, nfield, afcol->answer, abcol->answer,
ncol->answer, geo, 0))
G_fatal_error(_("Unable to build graph for vector map <%s>"), Vect_get_full_name(&In));
graph = Vect_net_get_graph(&In);
NetA_distance_from_points(graph, nodest, dst, prev);
/* Create table */
Fi = Vect_default_field_info(&Out, 1, NULL, GV_1TABLE);
Vect_map_add_dblink(&Out, 1, NULL, Fi->table, GV_KEY_COLUMN, Fi->database,
Fi->driver);
db_init_string(&sql);
driver = db_start_driver_open_database(Fi->driver, Fi->database);
if (driver == NULL)
G_fatal_error(_("Unable to open database <%s> by driver <%s>"),
Fi->database, Fi->driver);
db_set_error_handler_driver(driver);
sprintf(buf,
"create table %s ( cat integer, tcat integer, dist double precision)",
Fi->table);
db_set_string(&sql, buf);
G_debug(2, db_get_string(&sql));
if (db_execute_immediate(driver, &sql) != DB_OK) {
G_fatal_error(_("Unable to create table: '%s'"), db_get_string(&sql));
}
if (db_create_index2(driver, Fi->table, GV_KEY_COLUMN) != DB_OK)
G_warning(_("Cannot create index"));
if (db_grant_on_table
(driver, Fi->table, DB_PRIV_SELECT, DB_GROUP | DB_PUBLIC) != DB_OK)
G_fatal_error(_("Cannot grant privileges on table <%s>"), Fi->table);
db_begin_transaction(driver);
Vect_copy_head_data(&In, &Out);
Vect_hist_copy(&In, &Out);
Vect_hist_command(&Out);
from_nr = 0;
for (i = 1; i <= nlines; i++) {
if (varrayf->c[i]) {
int type = Vect_read_line(&In, Points, Cats, i);
int node, tcat, cat;
double cost;
dglInt32_t *vertex, vertex_id;
if (!Vect_cat_get(Cats, flayer, &cat))
continue;
if (type & GV_POINTS) {
node = Vect_find_node(&In, Points->x[0], Points->y[0], Points->z[0], 0, 0);
}
else {
Vect_get_line_nodes(&In, i, &node, NULL);
}
if (node < 1)
continue;
if (dst[node] < 0) {
/* unreachable */
from_nr++;
continue;
}
cost = dst[node] / (double)In.dgraph.cost_multip;
vertex = dglGetNode(graph, node);
vertex_id = node;
while (prev[vertex_id] != NULL) {
Vect_cat_set(on_path
[abs(dglEdgeGet_Id(graph, prev[vertex_id]))], 1,
cat);
vertex = dglEdgeGet_Head(graph, prev[vertex_id]);
vertex_id = dglNodeGet_Id(graph, vertex);
}
G_debug(3, "read line %d, vertex id %d", nodes_to_features[vertex_id], (int)vertex_id);
Vect_read_line(&In, NULL, TCats, nodes_to_features[vertex_id]);
if (!Vect_cat_get(TCats, tlayer, &tcat))
continue;
Vect_write_line(&Out, type, Points, Cats);
sprintf(buf, "insert into %s values (%d, %d, %f)", Fi->table, cat,
tcat, cost);
db_set_string(&sql, buf);
G_debug(3, db_get_string(&sql));
if (db_execute_immediate(driver, &sql) != DB_OK) {
G_fatal_error(_("Cannot insert new record: %s"),
db_get_string(&sql));
};
}
}
for (i = 1; i <= nlines; i++)
if (on_path[i]->n_cats > 0) {
int type = Vect_read_line(&In, Points, NULL, i);
Vect_write_line(&Out, type, Points, on_path[i]);
}
db_commit_transaction(driver);
db_close_database_shutdown_driver(driver);
Vect_build(&Out);
Vect_close(&In);
Vect_close(&Out);
for (i = 1; i <= nlines; i++)
Vect_destroy_cats_struct(on_path[i]);
G_free(on_path);
G_free(nodes_to_features);
G_free(dst);
G_free(prev);
if (from_nr)
G_warning(_n("%d 'from' feature was not reachable",
"%d 'from' features were not reachable",
from_nr), from_nr);
exit(EXIT_SUCCESS);
}
/*!
\brief Computes strongly connected components with Kosaraju's
two-pass algorithm
\param graph input graph
\param[out] component array of component ids
\return number of components
\return -1 on failure
*/
int NetA_strongly_connected_components(dglGraph_s * graph, int *component)
{
int nnodes, i;
dglInt32_t *stack, *order;
int *processed;
int stack_size, order_size, components;
dglInt32_t *cur_node;
dglNodeTraverser_s nt;
int have_node_costs;
dglInt32_t ncost;
if (graph->Version < 2) {
G_warning("Directed graph must be version 2 or 3 for NetA_strongly_connected_components()");
return -1;
}
components = 0;
nnodes = dglGet_NodeCount(graph);
stack = (dglInt32_t *) G_calloc(nnodes + 1, sizeof(dglInt32_t));
order = (dglInt32_t *) G_calloc(nnodes + 1, sizeof(dglInt32_t));
processed = (int *)G_calloc(nnodes + 1, sizeof(int));
if (!stack || !order || !processed) {
G_fatal_error(_("Out of memory"));
return -1;
}
for (i = 1; i <= nnodes; i++) {
component[i] = 0;
}
ncost = 0;
have_node_costs = dglGet_NodeAttrSize(graph);
order_size = 0;
dglNode_T_Initialize(&nt, graph);
for (cur_node = dglNode_T_First(&nt); cur_node;
cur_node = dglNode_T_Next(&nt)) {
dglInt32_t cur_node_id = dglNodeGet_Id(graph, cur_node);
if (!component[cur_node_id]) {
component[cur_node_id] = --components;
stack[0] = cur_node_id;
stack_size = 1;
while (stack_size) {
dglInt32_t *node, *edgeset, *edge;
dglEdgesetTraverser_s et;
dglInt32_t node_id = stack[stack_size - 1];
if (processed[node_id]) {
stack_size--;
order[order_size++] = node_id;
continue;
}
processed[node_id] = 1;
node = dglGetNode(graph, node_id);
edgeset = dglNodeGet_OutEdgeset(graph, node);
dglEdgeset_T_Initialize(&et, graph, edgeset);
for (edge = dglEdgeset_T_First(&et); edge;
edge = dglEdgeset_T_Next(&et)) {
dglInt32_t to;
to = dglNodeGet_Id(graph, dglEdgeGet_Tail(graph, edge));
if (!component[to]) {
component[to] = components;
/* do not go through closed nodes */
if (have_node_costs) {
memcpy(&ncost, dglNodeGet_Attr(graph, dglEdgeGet_Tail(graph, edge)),
sizeof(ncost));
}
if (ncost < 0)
processed[to] = 1;
stack[stack_size++] = to;
}
}
dglEdgeset_T_Release(&et);
}
}
}
dglNode_T_Release(&nt);
components = 0;
dglNode_T_Initialize(&nt, graph);
while (order_size) {
dglInt32_t cur_node_id = order[--order_size];
int cur_comp = component[cur_node_id];
if (cur_comp < 1) {
component[cur_node_id] = ++components;
stack[0] = cur_node_id;
stack_size = 1;
while (stack_size) {
dglInt32_t *node, *edgeset, *edge;
dglEdgesetTraverser_s et;
dglInt32_t node_id = stack[--stack_size];
node = dglGetNode(graph, node_id);
edgeset = dglNodeGet_InEdgeset(graph, node);
dglEdgeset_T_Initialize(&et, graph, edgeset);
for (edge = dglEdgeset_T_First(&et); edge;
edge = dglEdgeset_T_Next(&et)) {
dglInt32_t to;
to = dglNodeGet_Id(graph, dglEdgeGet_Head(graph, edge));
if (component[to] == cur_comp) {
component[to] = components;
/* do not go through closed nodes */
if (have_node_costs) {
memcpy(&ncost, dglNodeGet_Attr(graph, dglEdgeGet_Head(graph, edge)),
sizeof(ncost));
}
if (ncost >= 0)
stack[stack_size++] = to;
}
}
dglEdgeset_T_Release(&et);
}
}
}
dglNode_T_Release(&nt);
G_free(stack);
G_free(order);
G_free(processed);
return components;
}