# pgRouting Manual (3.3)

## pgr_withPointsDD - Proposed

- Supported versions: Latest (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.

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

Summary

    pgr_withPointsDD(edges_sql, points_sql, from_vids, distance [, directed] [, driving_side] [, details] [, equicost])
    RETURNS SET OF (seq, node, edge, cost, agg_cost)

Using defaults

- For a directed graph.

- The driving side is set as b both. So arriving/departing to/from the point(s) can be in any direction.

- No details are given about distance of other points of the query.

    pgr_withPointsDD(edges_sql, points_sql, start_vid, distance)
    RETURNS SET OF (seq, node, edge, cost, agg_cost)

Example

  From point \(1\) with \(agg\_cost <= 3.8\)

- For a directed graph.

- The driving side is set as b both. So arriving/departing to/from the point(s) can be in any direction.

- No details are given about distance of other points of the query.

    SELECT * FROM pgr_withPointsDD(
        'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
        'SELECT pid, edge_id, fraction, side from pointsOfInterest',
        -1, 3.8);
     seq | node | edge | cost | agg_cost
    -----+------+------+------+----------
       1 |   -1 |   -1 |    0 |        0
       2 |    1 |    1 |  0.4 |      0.4
       3 |    2 |    1 |  0.6 |      0.6
       4 |    5 |    4 |    1 |      1.6
       5 |    6 |    8 |    1 |      2.6
       6 |    8 |    7 |    1 |      2.6
       7 |   10 |   10 |    1 |      2.6
       8 |    7 |    6 |    1 |      3.6
       9 |    9 |    9 |    1 |      3.6
      10 |   11 |   11 |    1 |      3.6
      11 |   13 |   14 |    1 |      3.6
    (11 rows)

### Single vertex

Finds the driving distance depending on the optional parameters setup.

    pgr_withPointsDD(edges_sql, points_sql, from_vid,  distance [, directed] [, driving_side] [, details])
    RETURNS SET OF (seq, node, edge, cost, agg_cost)

Example

  Right side driving topology, from point \(1\) with \(agg\_cost <= 3.8\)

    SELECT * FROM pgr_withPointsDD(
        'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
        'SELECT pid, edge_id, fraction, side from pointsOfInterest',
        -1, 3.8,
        driving_side := 'r',
        details := true);
     seq | node | edge | cost | agg_cost
    -----+------+------+------+----------
       1 |   -1 |   -1 |    0 |        0
       2 |    1 |    1 |  0.4 |      0.4
       3 |    2 |    1 |    1 |      1.4
       4 |   -6 |    4 |  0.7 |      2.1
       5 |    5 |    4 |  0.3 |      2.4
       6 |    6 |    8 |    1 |      3.4
       7 |    8 |    7 |    1 |      3.4
       8 |   10 |   10 |    1 |      3.4
    (8 rows)

### Multiple vertices

Finds the driving distance depending on the optional parameters setup.

    pgr_withPointsDD(edges_sql, points_sql, from_vids, distance [, directed] [, driving_side] [, details] [, equicost])
    RETURNS SET OF (seq, node, edge, cost, agg_cost)

## Parameters

Parameter | Type | Description
--- | --- | ---
edges_sql | `TEXT` | Edges SQL query as described above.
points_sql | `TEXT` | Points SQL query as described above.
start_vid | `ANY-INTEGER` | Starting point id
distance | `ANY-NUMERICAL` | Distance from the start_pid
directed | `BOOLEAN` | (optional). When `false` the graph is considered as Undirected. Default is `true` which considers the graph as Directed.

driving_side

`CHAR`

(optional). Value in [‘b’, ‘r’, ‘l’, NULL] indicating if the driving side is:

  - In the right or left or

  - If it doesn’t matter with ‘b’ or NULL.

  - If column not present ‘b’ is considered.

details | `BOOLEAN` | (optional). When `true` the results will include the driving distance to the points with in the `distance`. Default is `false` which ignores other points of the points_sql.
equicost | `BOOLEAN` | (optional). When `true` the nodes will only appear in the closest start_v list. Default is `false` which resembles several calls using the single starting point signatures. Tie brakes are arbitrary.

## Inner query

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)

- When negative: edge (source, target) does not exist, therefore it’s not part of the graph.

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

Description of the Points SQL query

points_sql

  an SQL query, which should return a set of rows with the following columns:

Column | Type | Description
--- | --- | ---

pid

`ANY-INTEGER`

(optional) Identifier of the point.

- If column present, it can not be NULL.

- If column not present, a sequential identifier 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`

(optional) Value in [‘b’, ‘r’, ‘l’, NULL] indicating if the point is:

- In the right, left of the edge or

- If it doesn’t matter with ‘b’ or NULL.

- If column not present ‘b’ is considered.

Where:

ANY-INTEGER

  smallint, int, bigint

ANY-NUMERICAL

  smallint, int, bigint, real, float

## Result Columns

Column | Type | Description
--- | --- | ---
seq | `INT` | row sequence.
node | `BIGINT` | Identifier of the node within the Distance from `start_pid`. If `details =: true` a negative value is the identifier of a point.

edge

`BIGINT`

Identifier of the edge used to go from `node` to the next node in the path sequence.

  - `-1` when `start_vid` = `node`.

cost

`FLOAT`

Cost to traverse `edge`.

  - `0` when `start_vid` = `node`.

agg_cost

`FLOAT`

Aggregate cost from `start_vid` to `node`.

  - `0` when `start_vid` = `node`.

## Additional Examples

Examples for queries marked as `directed` with `cost` and `reverse_cost` columns.

The examples in this section use the following Network for queries marked as directed and cost and reverse_cost columns are used

Example

  Left side driving topology from point \(1\) with \(agg\_cost <= 3.8\), with details

    SELECT * FROM pgr_withPointsDD(
        'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
        'SELECT pid, edge_id, fraction, side from pointsOfInterest',
        -1, 3.8,
        driving_side := 'l',
        details := true);
     seq | node | edge | cost | agg_cost
    -----+------+------+------+----------
       1 |   -1 |   -1 |    0 |        0
       2 |    2 |    1 |  0.6 |      0.6
       3 |   -6 |    4 |  0.7 |      1.3
       4 |    5 |    4 |  0.3 |      1.6
       5 |    1 |    1 |    1 |      1.6
       6 |    6 |    8 |    1 |      2.6
       7 |    8 |    7 |    1 |      2.6
       8 |   10 |   10 |    1 |      2.6
       9 |   -3 |   12 |  0.6 |      3.2
      10 |   -4 |    6 |  0.7 |      3.3
      11 |    7 |    6 |  0.3 |      3.6
      12 |    9 |    9 |    1 |      3.6
      13 |   11 |   11 |    1 |      3.6
      14 |   13 |   14 |    1 |      3.6
    (14 rows)

Example

  From point \(1\) with \(agg\_cost <= 3.8\), does not matter driving side, with details

    SELECT * FROM pgr_withPointsDD(
        'SELECT id, source, target, cost, reverse_cost FROM edge_table ORDER BY id',
        'SELECT pid, edge_id, fraction, side from pointsOfInterest',
        -1, 3.8,
        driving_side := 'b',
        details := true);
     seq | node | edge | cost | agg_cost
    -----+------+------+------+----------
       1 |   -1 |   -1 |    0 |        0
       2 |    1 |    1 |  0.4 |      0.4
       3 |    2 |    1 |  0.6 |      0.6
       4 |   -6 |    4 |  0.7 |      1.3
       5 |    5 |    4 |  0.3 |      1.6
       6 |    6 |    8 |    1 |      2.6
       7 |    8 |    7 |    1 |      2.6
       8 |   10 |   10 |    1 |      2.6
       9 |   -3 |   12 |  0.6 |      3.2
      10 |   -4 |    6 |  0.7 |      3.3
      11 |    7 |    6 |  0.3 |      3.6
      12 |    9 |    9 |    1 |      3.6
      13 |   11 |   11 |    1 |      3.6
      14 |   13 |   14 |    1 |      3.6
    (14 rows)

The queries use the Sample Data network.

## See Also

- pgr_drivingDistance - Driving distance using dijkstra.

- pgr_alphaShape - Alpha shape computation.

Indices and tables

- Index

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