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pgr_withPointsDD - Proposed - pgRouting Manual (3.4)

Supported versions: Latest ( 3.4 ) 3.3 3.2 3.1 3.0
Unsupported versions: 2.6 2.5 2.4 2.3 2.2

`pgr_withPointsDD` - Proposed

pgr_withPointsDD - Returns the driving distance from a starting point.

Warning

Proposed functions for next mayor release.

They are not officially in the current release.
They will likely officially be part of the next mayor release:
- The functions make use of ANY-INTEGER and ANY-NUMERICAL
- Name might not change. (But still can)
- Signature might not change. (But still can)
- Functionality might not change. (But still can)
- pgTap tests have being done. But might need more.
- Documentation might need refinement.

images/boost-inside.jpeg — Boost Graph Inside

Availability

Version 2.2.0
- New proposed function

Description

Modify the graph to include points and using Dijkstra algorithm, extracts all the nodes and points that have costs less than or equal to the value **distance** from the starting point. The edges extracted will conform the corresponding spanning tree.

Signatures

      pgr_withPointsDD(
      
       Edges SQL
      
      ,
      
       Points SQL
      
      ,
      
       root vid
      
      ,
      
       distance
      
      , [
      
       options A
      
      ])
     
      pgr_withPointsDD(
      
       Edges SQL
      
      ,
      
       Points SQL
      
      ,
      
       root vids
      
      ,
      
       distance
      
      , [
      
       options B
      
      ])
     
       options A:
      
        [directed,
       
        driving_side,
       
        details]
       
       options B:
      
        [directed,
       
        driving_side,
       
        details,
       
        equicost]

RETURNS SET OF


       
        (seq,
       
       
        [start_vid],
       
       
        node,
       
       
        edge,
       
       
        cost,
       
       
        agg_cost)

OR EMPTY SET

Single vertex

pgr_withPointsDD( Edges SQL , Points SQL , root vid , distance , [ options ])

options:


        
         [directed,
        
        
         driving_side,
        
        
         details]

RETURNS SET OF

OR EMPTY SET

Example :: Right side driving topology, from point \(1\) within a distance of \(3.3\) with details.

      SELECT * FROM pgr_withPointsDD(
  'SELECT id, source, target, cost, reverse_cost FROM edges ORDER BY id',
  'SELECT pid, edge_id, fraction, side from pointsOfInterest',
  -1, 3.3,
  driving_side => 'r',
  details => true);
 seq  node  edge  cost  agg_cost
-----+------+------+------+----------
   1    -1    -1     0         0
   2     5     1   0.4       0.4
   3     6     1     1       1.4
   4    -6     4   0.7       2.1
   5     7     4   0.3       2.4
(5 rows)


     

Multiple vertices

pgr_withPointsDD( Edges SQL , Points SQL , root vids , distance , [ options ])

options:


        
         [directed,
        
        
         driving_side,
        
        
         details,
        
        
         equicost]

RETURNS SET OF

OR EMPTY SET

Example :: From point \(1\) and vertex \(16\) within a distance of \(3.3\) with equicost on a directed graph

      SELECT * FROM pgr_withPointsDD(
  'SELECT id, source, target, cost, reverse_cost FROM edges ORDER BY id',
  'SELECT pid, edge_id, fraction, side from pointsOfInterest',
  ARRAY[-1, 16], 3.3,
  driving_side => 'l',
  equicost => true);
 seq  start_vid  node  edge  cost  agg_cost
-----+-----------+------+------+------+----------
   1         -1    -1    -1     0         0
   2         -1     6     1   0.6       0.6
   3         -1     7     4     1       1.6
   4         -1     5     1     1       1.6
   5         -1     3     7     1       2.6
   6         -1     8    10     1       2.6
   7         16    16    -1     0         0
   8         16    11     9     1         1
   9         16    15    16     1         1
  10         16    17    15     1         1
  11         16    10     3     1         2
  12         16    12    11     1         2
(12 rows)


     

Parameters

Column	Type	Description
Edges SQL	`TEXT`	Edges SQL as described below
Points SQL	`TEXT`	Points SQL as described below
Root vid	`BIGINT`	Identifier of the root vertex of the tree. Negative values represent a point
Root vids	`ARRAY` [ ANY-INTEGER ]	Array of identifiers of the root vertices. Negative values represent a point \(0\) values are ignored For optimization purposes, any duplicated value is ignored.
distance	`FLOAT`	Upper limit for the inclusion of a node in the result.

Optional parameters

Column	Type	Default	Description
`directed`	`BOOLEAN`	`true`	When `true` the graph is considered Directed When `false` the graph is considered as Undirected .

With points optional parameters

Parameter	Type	Default	Description
`driving_side`	`CHAR`	`b`	Value in [ `r` , `l` , `b` ] indicating if the driving side is: `r` for right driving side. `l` for left driving side. `b` for both.
`details`	`BOOLEAN`	`false`	When `true` the results will include the points that are in the path. When `false` the results will not include the points that are in the path.

Parameter

Type

Default

Description

driving_side

CHAR

b

Value in [ r , l , b ] indicating if the driving side is:

r for right driving side.
l for left driving side.
b for both.

details

BOOLEAN

false

When true the results will include the points that are in the path.
When false the results will not include the points that are in the path.

Driving distance optional parameters

Column	Type	Default	Description
`equicost`	`BOOLEAN`	`true`	When `true` the node will only appear in the closest `from_v` list. When `false` which resembles several calls using the single starting point signatures. Tie brakes are arbitrary.

Inner Queries

Edges SQL

Column	Type	Default	Description
`id`	ANY-INTEGER		Identifier of the edge.
`source`	ANY-INTEGER		Identifier of the first end point vertex of the edge.
`target`	ANY-INTEGER		Identifier of the second end point vertex of the edge.
`cost`	ANY-NUMERICAL		Weight of the edge ( `source` , `target` )
`reverse_cost`	ANY-NUMERICAL	-1	Weight of the edge ( `target` , `source` ) When negative: edge ( `target` , `source` ) does not exist, therefore it’s not part of the graph.

Where:

ANY-INTEGER :: SMALLINT , INTEGER , BIGINT
ANY-NUMERICAL :: SMALLINT , INTEGER , BIGINT , REAL , FLOAT

Points SQL

Parameter	Type	Default	Description
`pid`	ANY-INTEGER	value	Identifier of the point. Use with positive value, as internally will be converted to negative value If column is present, it can not be NULL. If column is not present, a sequential negative value will be given automatically.
`edge_id`	ANY-INTEGER		Identifier of the "closest" edge to the point.
`fraction`	ANY-NUMERICAL		Value in <0,1> that indicates the relative postition from the first end point of the edge.
`side`	`CHAR`	`b`	Value in [ `b` , `r` , `l` , `NULL` ] indicating if the point is: In the right `r` , In the left `l` , In both sides `b` , `NULL`

Where:

ANY-INTEGER :: SMALLINT , INTEGER , BIGINT
ANY-NUMERICAL :: SMALLINT , INTEGER , BIGINT , REAL , FLOAT

Result Columns

RETURNS SET OF (seq, [start_vid], node, edge, cost, agg_cost)

Parameter	Type	Description
`seq`	`BIGINT`	Sequential value starting from \(1\) .
`[start_vid]`	`BIGINT`	Identifier of the root vertex.
`node`	`BIGINT`	Identifier of `node` within the limits from `from_v` .
`edge`	`BIGINT`	Identifier of the `edge` used to arrive to `node` . \(0\) when `node` = `from_v` .
`cost`	`FLOAT`	Cost to traverse `edge` .
`agg_cost`	`FLOAT`	Aggregate cost from `from_v` to `node` .

Where:

ANY-INTEGER :: SMALLINT, INTEGER, BIGINT
ANY-NUMERIC :: SMALLINT, INTEGER, BIGINT, REAL, FLOAT, NUMERIC

Additional Examples

Use pgr_findCloseEdges in the Points SQL .

Find the driving distance from the two closest locations on the graph of point (2.9, 1.8) .

      SELECT * FROM pgr_withPointsDD(
  $e$ SELECT * FROM edges $e$,
  $p$ SELECT edge_id, round(fraction::numeric, 2) AS fraction, side
      FROM pgr_findCloseEdges(
        $$SELECT id, geom FROM edges$$,
        (SELECT ST_POINT(2.9, 1.8)),
        0.5, cap => 2)
  $p$,
  ARRAY[-1, -2], 2.3,
  driving_side => 'r',
  details => true);
 seq  start_vid  node  edge  cost  agg_cost
-----+-----------+------+------+------+----------
   1         -1    -1    -1     0         0
   2         -1    11     5   0.2       0.2
   3         -1     7     8     1       1.2
   4         -1    12    11     1       1.2
   5         -1    16     9     1       1.2
   6         -1    -2     8   0.9       2.1
   7         -1     3     7     1       2.2
   8         -1     6     4     1       2.2
   9         -1     8    10     1       2.2
  10         -1    15    16     1       2.2
  11         -1    17    13     1       2.2
  12         -2    -2    -1     0         0
  13         -2    11     8   0.1       0.1
  14         -2     7     8     1       1.1
  15         -2    12    11     1       1.1
  16         -2    16     9     1       1.1
  17         -2     3     7     1       2.1
  18         -2     6     4     1       2.1
  19         -2     8    10     1       2.1
  20         -2    15    16     1       2.1
  21         -2    17    13     1       2.1
(21 rows)


     

Point \(-1\) corresponds to the closest edge from point (2.9,1.8) .
Point \(-2\) corresponds to the next close edge from point (2.9,1.8) .

Driving side does not matter

From point \(1\) within a distance of \(3.3\) , does not matter driving side, with details.

      SELECT * FROM pgr_withPointsDD(
  'SELECT id, source, target, cost, reverse_cost FROM edges ORDER BY id',
  'SELECT pid, edge_id, fraction, side from pointsOfInterest',
  -1, 3.3,
  driving_side => 'b',
  details => true);
 seq  node  edge  cost  agg_cost
-----+------+------+------+----------
   1    -1    -1     0         0
   2     5     1   0.4       0.4
   3     6     1   0.6       0.6
   4    -6     4   0.7       1.3
   5     7     4   0.3       1.6
   6     3     7     1       2.6
   7     8    10     1       2.6
   8    11     8     1       2.6
   9    -3    12   0.6       3.2
  10    -4     6   0.7       3.3
(10 rows)


     

pgr_withPointsDD - Proposed - pgRouting Manual (3.4)