1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
:file: This file is part of the pgRouting project.
:copyright: Copyright (c) 2018-2026 pgRouting developers
:license: Creative Commons Attribution-Share Alike 3.0 https://creativecommons.org/licenses/by-sa/3.0
.. index::
single: Prim Family ; pgr_prim
single: Spanning Tree Category ; pgr_prim
single: prim
|
``pgr_prim``
===============================================================================
``pgr_prim`` — Minimum spanning forest of a graph using Prim's algorithm.
.. rubric:: Availability
* Version 3.0.0
* New official function.
Description
-------------------------------------------------------------------------------
This algorithm finds the minimum spanning forest in a possibly disconnected
graph using Prim's algorithm.
**The main characteristics are:**
.. include:: prim-family.rst
:start-after: prim-description-start
:end-before: prim-description-end
- EMPTY SET is returned when there are no edges in the graph.
|Boost| Boost Graph Inside
Signatures
-------------------------------------------------------------------------------
.. rubric:: Summary
.. admonition:: \ \
:class: signatures
| pgr_prim(`Edges SQL`_)
| Returns set of |result-mst|
| OR EMPTY SET
:Example: Minimum spanning forest of a subgraph
.. literalinclude:: prim.queries
:start-after: -- q1
:end-before: -- q2
Parameters
-------------------------------------------------------------------------------
.. include:: pgRouting-concepts.rst
:start-after: only_edge_param_start
:end-before: only_edge_param_end
Inner Queries
-------------------------------------------------------------------------------
Edges SQL
...............................................................................
.. include:: pgRouting-concepts.rst
:start-after: basic_edges_sql_start
:end-before: basic_edges_sql_end
Result columns
-------------------------------------------------------------------------------
.. include:: pgRouting-concepts.rst
:start-after: r-edge-cost-start
:end-before: r-edge-cost-end
See Also
-------------------------------------------------------------------------------
* :doc:`spanningTree-category`
* :doc:`prim-family`
* :doc:`sampledata`
* `Boost: Prim's algorithm documentation
<https://www.boost.org/libs/graph/doc/prim_minimum_spanning_tree.html>`__
* `Wikipedia: Prim's algorithm
<https://en.wikipedia.org/wiki/Prim%27s_algorithm>`__
.. rubric:: Indices and tables
* :ref:`genindex`
* :ref:`search`
|
