# pgr_vidsToDMatrix - Deprecated Function¶

Warning

This function is deprecated!!!

• Is no longer supported.
• May be removed from future versions.
• There is no replacement.

## Name¶

pgr_vidsToDMatrix - Creates a distances matrix from an array of vertex_id.

## Synopsis¶

This function takes an array of vertex_id, the original array of points used to generate the array of vertex_id, an edge table name and a tol. It then computes kdijkstra() distances for each vertex to all the other vertices and creates a symmetric distance matrix suitable for TSP. The pnt array and the tol are used to establish a BBOX for limiting selection of edges. The extents of the points is expanded by tol.

The function returns:

• record - with two fields as describe here
• dmatrix: float8[] - the distance matrix suitable to pass to pgrTSP() function.
• ids: integer[] - an array of ids for the distance matrix.
record pgr_vidsToDMatrix(IN vids integer[], IN pnts geometry[], IN edges text, tol float8 DEFAULT(0.1), OUT dmatrix double precision[], OUT ids integer[])


## Description¶

Parameters

vids: integer[] - An array of vertex_id. geometry[] - An array of point geometries that approximates the extents of the vertex_id. text - The edge table to be used for the conversion. float8 - The amount to expand the BBOX extents of pnts when building the graph.

Warning

• we compute a symmetric matrix because TSP requires that so the distances are better the Euclidean but but are not perfect
• kdijkstra() can fail to find a path between some of the vertex ids. We to not detect this other than the cost might get set to -1.0, so the dmatrix should be checked for this as it makes it invalid for TSP

History

• Proposed in version 2.1.0

## Examples¶

This example uses existing data of points.

SELECT * FROM pgr_vidstodmatrix(
ARRAY[1,2,3,5],
ARRAY(select the_geom FROM edge_table_vertices_pgr WHERE id in (1,2,3,5)),
'edge_table'
);
NOTICE:  Deprecated function pgr_vidsToDMatrix
dmatrix                  |    ids
-------------------------------------------+-----------
{{0,1,4,2},{1,0,3,1},{4,3,0,2},{2,1,2,0}} | {1,2,3,5}
(1 row)

This example uses points that are not part of the graph.
SELECT * FROM pgr_vidstodmatrix(
pgr_pointstovids(pgr_texttopoints('2,0;2,1;3,1;2,2', 0), 'edge_table'),
pgr_texttopoints('2,0;2,1;3,1;2,2', 0),
'edge_table');
NOTICE:  Deperecated function: pgr_textToPoints
NOTICE:  Deperecated function: pgr_textToPoints
NOTICE:  Deprecated function pgr_vidsToDMatrix
dmatrix                  |    ids
-------------------------------------------+-----------
{{0,1,4,2},{1,0,3,1},{4,3,0,2},{2,1,2,0}} | {1,2,3,5}
(1 row)


This example shows how this can be used in the context of feeding the results into pgr_tsp() function.

SELECT * FROM pgr_tsp(
(SELECT dMatrix FROM pgr_vidstodmatrix(
pgr_pointstovids(pgr_texttopoints('2,0;2,1;3,1;2,2', 0), 'edge_table'),
pgr_texttopoints('2,0;2,1;3,1;2,2', 0),
'edge_table')
),
1
);
NOTICE:  Deperecated function: pgr_textToPoints
NOTICE:  Deperecated function: pgr_textToPoints
NOTICE:  Deprecated function pgr_vidsToDMatrix
seq | id
-----+----
0 |  1
1 |  2
2 |  3
3 |  0
(4 rows)


This example uses the Sample Data network.