Name¶

pgr_pointsToDMatrix - Creates a distance matrix from an array of points.

Synopsis¶

Create a distance symetric distance matrix suitable for TSP using Euclidean distances based on the st_distance(). You might want to create a variant of this the uses st_distance_sphere() or st_distance_spheriod() or some other function.

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_pointsToDMatrix(pnts geometry[], OUT dmatrix double precision[], OUT ids integer[])

Description¶

Paramters

History

• Proposed in version 2.1.0

Examples¶

SELECT * FROM pgr_pointstodmatrix(pgr_texttopoints('2,0;2,1;3,1;2,2', 0));
                                              dmatrix                                              |    ids    
---------------------------------------------------------------------------------------------------+-----------
 {{0,1,1.4142135623731,2},{1,0,1,1},{1.4142135623731,1,0,1.4142135623731},{2,1,1.4142135623731,0}} | {1,2,3,4}
(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_pointstodmatrix(pgr_texttopoints('2,0;2,1;3,1;2,2', 0))
    ),
    1
);
 seq | id 
-----+----
   0 |  1
   1 |  3
   2 |  2
   3 |  0
(4 rows)

See Also¶

• pgr_vidsToDMatrix - convert a point geometry to the closest vertex_id of an edge..
• pgr_tsp - Traveling Sales Person

Indices and tables

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