[pgrouting-users] Working with Driving Distance

Roger André randre at gmail.com
Tue Dec 21 23:12:07 EST 2010


Ok, so using what I think is the correct SQL syntax, I get a different sort
of error:

eligibility=# SELECT the_geom FROM driving_distance('edges', 2512140,
7040129, 2000, 'length', 'length', false, false);
NOTICE:  SRID: 2276
NOTICE:  Query: SELECT gid, the_geom FROM points_as_polygon('SELECT
a.vertex_id::integer AS id, b.x1::double precision AS x, b.y1::double
precision AS y FROM driving_distance(''''SELECT gid AS
id,source::integer,target::integer, length::double precision AS cost,
length::double precision as reverse_cost FROM edges WHERE
setsrid(''''''''BOX3D(2510140 7038129, 2514140 7042129)''''''''::BOX3D,
2276) && the_geom  '''', (SELECT id FROM
find_node_by_nearest_link_within_distance(''''POINT(2512140
7040129)'''',200,''''edges'''')),2000,true,true) a, (SELECT * FROM edges
WHERE setsrid(''''BOX3D(2510140 7038129, 2514140 7042129)''''::BOX3D,
2276)&&the_geom) b WHERE a.vertex_id = b.source')
ERROR:  function find_node_by_nearest_link_within_distance(unknown, integer,
unknown) does not exist
LINE 1: ...)''::BOX3D, 2276) && the_geom  ', (SELECT id FROM find_node_...
                                                             ^
HINT:  No function matches the given name and argument types. You might need
to add explicit type casts.
QUERY:  SELECT a.vertex_id::integer AS id, b.x1::double precision AS x,
b.y1::double precision AS y FROM driving_distance('SELECT gid AS
id,source::integer,target::integer, length::double precision AS cost,
length::double precision as reverse_cost FROM edges WHERE
setsrid(''BOX3D(2510140 7038129, 2514140 7042129)''::BOX3D, 2276) &&
the_geom  ', (SELECT id FROM
find_node_by_nearest_link_within_distance('POINT(2512140
7040129)',200,'edges')),2000,true,true) a, (SELECT * FROM edges WHERE
setsrid('BOX3D(2510140 7038129, 2514140 7042129)'::BOX3D, 2276)&&the_geom) b
WHERE a.vertex_id = b.source
CONTEXT:  PL/pgSQL function "points_as_polygon" line 17 at FOR over EXECUTE
statement
PL/pgSQL function "driving_distance" line 25 at FOR over EXECUTE statement

Still puzzling this one out.
--


On Tue, Dec 21, 2010 at 7:55 PM, Roger André <randre at gmail.com> wrote:

> Hi Daniel,
>
> Thanks for your reply.  I checked, and it appears that I have that wrapper
> function installed.  Here is what my pgrouting install dir looks like:
>
> $ pwd
> /usr/local/pgrouting-1.05/extra/driving_distance/sql
>
> $ ll
> total 36
> drwxr-xr-x 3 15036 users 4096 2010-12-21 15:58 ./
> drwxr-xr-x 5 15036 users 4096 2010-12-21 15:58 ../
> drwxr-xr-x 2 root  root  4096 2010-12-21 15:58 CMakeFiles/
> -rw-r--r-- 1 root  root  1811 2010-12-21 15:58 cmake_install.cmake
> -rw-r--r-- 1 15036 users  134 2010-11-16 18:42 CMakeLists.txt
> -rw-r--r-- 1 root  root  5540 2010-12-21 15:58 Makefile
> -rw-r--r-- 1 15036 users 1757 2010-11-16 18:42 routing_dd.sql
> -rw-r--r-- 1 15036 users 3790 2010-11-16 18:42 routing_dd_wrappers.sql
>
> And I did make sure to run both SQL files against the database my roads are
> stored in.
>
>   482  psql -d eligibility -f routing_dd.sql
>   483  psql -d eligibility -f routing_dd_wrappers.sql
>   490  psql -d eligibility -f routing_tsp.sql
>   491  psql -d eligibility -f routing_tsp_wrappers.sql
>
> I will review your usage instructions and see if I'm missing anything.
>
> Roger
> --
>
> On Tue, Dec 21, 2010 at 5:51 PM, Daniel Kastl <daniel at georepublic.de>wrote:
>
>> Hi Roger,
>>
>> You're using the "core" function, I think.
>> You could use the driving_distance wrapper function, which will return you
>> a polyogon.
>> For that you need to load this SQL:
>> https://github.com/pgRouting/pgrouting/blob/master/extra/driving_distance/sql/routing_dd_wrappers.sql
>> You can also find it in the directory where the other pgRouting SQL files
>> are.
>>
>> The function will take these parameters then:
>>
>> driving_distance(table_name varchar, x double precision, y double
>> precision,
>>         distance double precision, cost varchar, reverse_cost varchar,
>> directed boolean, has_reverse_cost boolean)
>>
>> X,Y are the coordinates you take as a center point.
>> You can take the returned polygon then and do other spatial queries.
>>
>> Best regards,
>> Daniel
>>
>>
>>
>> 2010/12/22 Roger André <randre at gmail.com>
>>
>>> Hi All,
>>>
>>> I need to generate some maps that show all of the road segments that are
>>> within a certain distance of specific points.  I have been able to generate
>>> some answers using the driving_distance function, but am not sure what to do
>>> with them.  Here's what I get:
>>>
>>> # SELECT * FROM driving_distance('SELECT gid AS id, source, target,
>>> length::double precision AS cost FROM edges',49,2000,false,false);
>>>  vertex_id | edge_id |       cost
>>> -----------+---------+------------------
>>>         15 |       9 | 1854.34547361565
>>>         20 |     104 | 1549.85630678904
>>>         22 |      68 | 858.367668935802
>>>         23 |     125 | 1466.02479201359
>>>         24 |      75 | 801.137871846872
>>>         25 |     125 | 1169.02817170106
>>>         26 |     106 | 1296.98197602289
>>>         48 |      71 | 902.595810873304
>>>         49 |     106 |                0
>>>         51 |      74 | 1948.07551810288
>>>         52 |      75 | 1620.93404864578
>>> (11 rows)
>>>
>>> These answers seem legit, but I'm not sure what to do with them.
>>> Ultimately, I need to show both the minimum enclosing polygon that
>>> "surrounds" all of the road segments, as well as the road segments
>>> themselves.  Can someone please give me some pointers as to what I can do to
>>> accomplish this?
>>>
>>> Thanks,
>>>
>>> Roger
>>> --
>>>
>>> _______________________________________________
>>> Pgrouting-users mailing list
>>> Pgrouting-users at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/pgrouting-users
>>>
>>>
>>
>>
>> --
>> Georepublic UG & Georepublic Japan
>> eMail: daniel.kastl at georepublic.de
>> Web: http://georepublic.de
>>
>> _______________________________________________
>> Pgrouting-users mailing list
>> Pgrouting-users at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/pgrouting-users
>>
>>
>
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