[pgrouting-users] I would like some help with creating a Distance Matrix

[Yukie Hime]

Hi,

I am new to using GIS software and the SQL language. I have installed
PostgreSQL 9.2.4 and pgRouting 2.0 dev on Windows 7. I've been using the
SQL window from pgAdmin3, and DB Manager from QGIS to follow the tutorials
on http://anitagraser.com/tag/pgrouting/

I was thinking of using a combination
of find_node_by_nearest_link_within_distance and pgr_kdijkstraCost in order
to create my Distance Matrix where the vertices are set out like square
grid points. For each grid point, I want to create a table that lists the
closest 8 grid points, with columns for the source vertexID, target
vertexID, x1, y1, x2, y2, distance in km. I have a .shp file with the grid
points, and a .shp file with the road network. I want the final results to
be outputted into a .csv file.

So far, I haven't managed to get past getting
find_node_by_nearest_link_within_distance to work. I can run
pgr_kdijkstraCost using the example on
http://docs.pgrouting.org/dev/src/kdijkstra/doc/index.html just fine.

I also ran pgrouting.sql and matching.sql in the SQL window, and then
finally the following code:


SELECT id(foo.x)
FROM (
   SELECT find_node_by_nearest_link_within_distance(
    'POINT(103.6953034 1.381645751)',
    0.5,
    'public.roads')::link_point as x
) AS foo


... and then I get the following error:


ERROR:  column "the_geom" does not exist
LINE 1: select getsrid(the_geom) as srid from public.roads where gid...
                       ^
QUERY:  select getsrid(the_geom) as srid from public.roads where gid =
(select min(gid) from public.roads)
CONTEXT:  PL/pgSQL function
find_node_by_nearest_link_within_distance(character varying,double
precision,character varying) line 13 at FOR over EXECUTE statement


********** Error **********

ERROR: column "the_geom" does not exist
SQL state: 42703
Context: PL/pgSQL function
find_node_by_nearest_link_within_distance(character varying,double
precision,character varying) line 13 at FOR over EXECUTE statement


I am now completely lost as to what to do. Some kind advice would be
greatly appreciated.


Regards,
Vi
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/pgrouting-users/attachments/20130905/97408259/attachment.html>