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/*PGR-GNU*****************************************************************
File: randomSpanningTree.sql
Generated with Template by:
Copyright (c) 2016 pgRouting developers
Mail: project@pgrouting.org
Function's developer:
Copyright (c) 2018 Aditya Pratap Singh
Mail: adityapratap.singh28@gmail.com
------
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
********************************************************************PGR-GNU*/
-----------------------
-- pgr_randomSpanTree
-----------------------
--vnone
CREATE FUNCTION pgr_randomSpanTree(
TEXT, -- edges_sql (required)
BIGINT, -- root (required)
directed BOOLEAN DEFAULT TRUE,
OUT seq BIGINT, -- Seq
OUT root_vertex BIGINT,
OUT edge BIGINT, -- Edge linked to that node
OUT cost FLOAT, -- Cost of edge
OUT tree_cost FLOAT) -- Spanning tree cost
RETURNS SETOF RECORD AS
$BODY$
DECLARE
connectedComponent BIGINT;
BEGIN
SELECT COUNT(DISTINCT component) INTO connectedComponent
FROM pgr_connectedComponents(
'SELECT id, source, target, cost, reverse_cost
FROM edge_table'
);
IF (connectedComponent = 1) THEN
SELECT seq, root_vertex, edge, cost, tree_cost
FROM _pgr_randomSpanTree(_pgr_get_statement($1), $2, $3, TRUE);
ELSE
SELECT seq, root_vertex, edge, cost, tree_cost
FROM _pgr_randomSpanTree(_pgr_get_statement($1), $2, $3, FALSE);
END IF;
END;
$BODY$
LANGUAGE plpgsql VOLATILE STRICT;
COMMENT ON FUNCTION pgr_randomSpanTree(TEXT, BIGINT)
IS 'pgr_randomSpanTree
- EXPERIMENTAL
- Undirected graph
- Parameters:
- Edges SQL with columns: id, source, target, cost [,reverse_cost]
- Root vertex identifier
- Optional Parameters
- directed: default := ''true''
- Documentation:
- ${PROJECT_DOC_LINK}/pgr_randomSpanTree.html
';
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