[pgrouting-users] Problem with topology using sample data in the manual

HuanChun Ye huanchunye at athentek.com
Fri May 13 20:56:41 PDT 2016


I am working through the examples in the manual (v2.2) using the sample
data, but encountered a problem with topology, as described below. I
apologize for the verbosity, but I want to show the exact steps leading to
the problem, starting with just after importing the sample data:

pgr_sample=# select * from edge_table;
 id | dir | source | target | cost | reverse_cost | x1  | y1  |       x2
    | y2  |                                      the_geom

----+-----+--------+--------+------+--------------+-----+-----+----------------+-----+-----------------------------------------------------------------------------------
-
  1 | B   |        |        |    1 |            1 |   2 |   0 |
 2 |   1 |
010200000002000000000000000000004000000000000000000000000000000040000000000000F03F
  2 | TF  |        |        |   -1 |            1 |   2 |   1 |
 3 |   1 |
0102000000020000000000000000000040000000000000F03F0000000000000840000000000000F03F
  3 | TF  |        |        |   -1 |            1 |   3 |   1 |
 4 |   1 |
0102000000020000000000000000000840000000000000F03F0000000000001040000000000000F03F
  4 | B   |        |        |    1 |            1 |   2 |   1 |
 2 |   2 |
0102000000020000000000000000000040000000000000F03F00000000000000400000000000000040
  5 | FT  |        |        |    1 |           -1 |   3 |   1 |
 3 |   2 |
0102000000020000000000000000000840000000000000F03F00000000000008400000000000000040
  6 | B   |        |        |    1 |            1 |   0 |   2 |
 1 |   2 |
01020000000200000000000000000000000000000000000040000000000000F03F0000000000000040
  7 | B   |        |        |    1 |            1 |   1 |   2 |
 2 |   2 |
010200000002000000000000000000F03F000000000000004000000000000000400000000000000040
  8 | B   |        |        |    1 |            1 |   2 |   2 |
 3 |   2 |
0102000000020000000000000000000040000000000000004000000000000008400000000000000040
  9 | B   |        |        |    1 |            1 |   3 |   2 |
 4 |   2 |
0102000000020000000000000000000840000000000000004000000000000010400000000000000040
 10 | B   |        |        |    1 |            1 |   2 |   2 |
 2 |   3 |
0102000000020000000000000000000040000000000000004000000000000000400000000000000840
 11 | FT  |        |        |    1 |           -1 |   3 |   2 |
 3 |   3 |
0102000000020000000000000000000840000000000000004000000000000008400000000000000840
 12 | FT  |        |        |    1 |           -1 |   2 |   3 |
 3 |   3 |
0102000000020000000000000000000040000000000000084000000000000008400000000000000840
 13 | FT  |        |        |    1 |           -1 |   3 |   3 |
 4 |   3 |
0102000000020000000000000000000840000000000000084000000000000010400000000000000840
 14 | B   |        |        |    1 |            1 |   2 |   3 |
 2 |   4 |
0102000000020000000000000000000040000000000000084000000000000000400000000000001040
 15 | B   |        |        |    1 |            1 |   4 |   2 |
 4 |   3 |
0102000000020000000000000000001040000000000000004000000000000010400000000000000840
 16 | B   |        |        |    1 |            1 |   4 |   1 |
 4 |   2 |
0102000000020000000000000000001040000000000000F03F00000000000010400000000000000040
 17 | B   |        |        |    1 |            1 | 0.5 | 3.5 |
1.999999999999 | 3.5 |
010200000002000000000000000000E03F0000000000000C4068EEFFFFFFFFFF3F0000000000000C40
 18 | B   |        |        |    1 |            1 | 3.5 | 2.3 |
 3.5 |   4 |
0102000000020000000000000000000C4066666666666602400000000000000C400000000000001040
(18 rows)


pgr_sample=# select pgr_createTopology('edge_table', 0.001);
NOTICE:  PROCESSING:
NOTICE:  pgr_createTopology('edge_table', 0.001, 'the_geom', 'id',
'source', 'target', rows_where := 'true', clean := f)
NOTICE:  Performing checks, please wait .....
NOTICE:  Creating Topology, Please wait...
NOTICE:  -------------> TOPOLOGY CREATED FOR  18 edges
NOTICE:  Rows with NULL geometry or NULL id: 0
NOTICE:  Vertices table for table public.edge_table is:
public.edge_table_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createtopology
--------------------
 OK
(1 row)


pgr_sample=# select pgr_analyzeGraph('edge_table', 0.001);
NOTICE:  PROCESSING:
NOTICE:
 pgr_analyzeGraph('edge_table',0.001,'the_geom','id','source','target','true')
NOTICE:  Performing checks, please wait ...
NOTICE:  Analyzing for dead ends. Please wait...
NOTICE:  Analyzing for gaps. Please wait...
NOTICE:  Analyzing for isolated edges. Please wait...
NOTICE:  Analyzing for ring geometries. Please wait...
NOTICE:  Analyzing for intersections. Please wait...
NOTICE:              ANALYSIS RESULTS FOR SELECTED EDGES:
NOTICE:                    Isolated segments: 2
NOTICE:                            Dead ends: 7
NOTICE:  Potential gaps found near dead ends: 1
NOTICE:               Intersections detected: 1
NOTICE:                      Ring geometries: 0
 pgr_analyzegraph
------------------
 OK
(1 row)


pgr_sample=# select pgr_nodeNetwork('edge_table', 0.001);
NOTICE:  PROCESSING:
NOTICE:  pgr_nodeNetwork('edge_table', 0.001, 'id', 'the_geom', 'noded',
'<NULL>',  f)
NOTICE:  Performing checks, please wait .....
NOTICE:  Processing, please wait .....
NOTICE:    Splitted Edges: 2
NOTICE:   Untouched Edges: 16
NOTICE:       Total original Edges: 18
NOTICE:   Edges generated: 4
NOTICE:   Untouched Edges: 16
NOTICE:         Total New segments: 20
NOTICE:   New Table: public.edge_table_noded
NOTICE:  ----------------------------------
 pgr_nodenetwork
-----------------
 OK
(1 row)


pgr_sample=# select pgr_createTopology('edge_table_noded', 0.001);
NOTICE:  PROCESSING:
NOTICE:  pgr_createTopology('edge_table_noded', 0.001, 'the_geom', 'id',
'source', 'target', rows_where := 'true', clean := f)
NOTICE:  Performing checks, please wait .....
NOTICE:  Creating Topology, Please wait...
NOTICE:  -------------> TOPOLOGY CREATED FOR  20 edges
NOTICE:  Rows with NULL geometry or NULL id: 0
NOTICE:  Vertices table for table public.edge_table_noded is:
public.edge_table_noded_vertices_pgr
NOTICE:  ----------------------------------------------
 pgr_createtopology
--------------------
 OK
(1 row)


pgr_sample=# select pgr_analyzeGraph('edge_table_noded', 0.001);
NOTICE:  PROCESSING:
NOTICE:
 pgr_analyzeGraph('edge_table_noded',0.001,'the_geom','id','source','target','true')
NOTICE:  Performing checks, please wait ...
NOTICE:  Analyzing for dead ends. Please wait...
NOTICE:  Analyzing for gaps. Please wait...
NOTICE:  Analyzing for isolated edges. Please wait...
NOTICE:  Analyzing for ring geometries. Please wait...
NOTICE:  Analyzing for intersections. Please wait...
NOTICE:              ANALYSIS RESULTS FOR SELECTED EDGES:
NOTICE:                    Isolated segments: 1
NOTICE:                            Dead ends: 7
NOTICE:  Potential gaps found near dead ends: 1
NOTICE:               Intersections detected: 0
NOTICE:                      Ring geometries: 0
 pgr_analyzegraph
------------------
 OK
(1 row)


pgr_sample=# SELECT a.*
pgr_sample-# FROM edge_table_noded a, edge_table_noded_vertices_pgr b,
edge_table_noded_vertices_pgr c
pgr_sample-# WHERE a.source=b.id AND b.cnt=1 AND a.target=c.id AND c.cnt=1;
 id | old_id | sub_id | source | target |
   the_geom
----+--------+--------+--------+--------+------------------------------------------------------------------------------------
 20 |     17 |      1 |     17 |     18 |
010200000002000000000000000000E03F0000000000000C4068EEFFFFFFFFFF3F0000000000000C40
(1 row)


So the original node id 17, which is a nearly touching T-intersection,
remains isolated. This is in contrast to the output shown in the manual,
which shows the following:

SELECT pgr_analyzegraph('edge_table_noded', 0.001);NOTICE:
PROCESSING:NOTICE:
pgr_analyzeGraph('edge_table_noded',0.001,'the_geom','id','source','target','true')NOTICE:
 Performing checks, pelase wait...NOTICE:  Analyzing for dead ends.
Please wait...NOTICE:  Analyzing for gaps. Please wait...NOTICE:
Analyzing for isolated edges. Please wait...NOTICE:  Analyzing for
ring geometries. Please wait...NOTICE:  Analyzing for intersections.
Please wait...NOTICE:              ANALYSIS RESULTS FOR SELECTED
EDGES:NOTICE:                    Isolated segments: 0NOTICE:
                 Dead ends: 6NOTICE:  Potential gaps found near dead
ends: 0NOTICE:               Intersections detected: 0NOTICE:
            Ring geometries: 0pgr_createtopology--------------------
 OK(1 row)

I tried the following but none helped:
- increasing the value of tolerance up to 0.5
- setting the SRID of the geometry column
- converting data to .osm file and run osm2pgrouting

I am using the following versions on Windows 10 64-bit PC:

pgr_sample=# select version(), postgis_full_version(), pgr_version();
                           version                           |

postgis_full_version
                                                        |
 pgr_version
-------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------
--------------------------------------------------------+-----------------------------------------------
 PostgreSQL 9.5.2, compiled by Visual C++ build 1800, 64-bit |
POSTGIS="2.2.2 r14797" GEOS="3.5.0-CAPI-1.9.0 r4090" PROJ="Rel. 4.9.1, 04
March 2015" GDAL="GDAL 2.0.2, re
leased 2016/01/26" LIBXML="2.7.8" LIBJSON="0.12" RASTER |
(2.2.0,pgrouting-2.2.0,afc622e,master,1.59.0)
(1 row)

Thanks in advance for your help!
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