[pgrouting-dev] pgr_alphaShape

[Stephen Mather]

Ahem, sent before I was done:

WITH DD AS (
SELECT seq, id1 AS node, cost
         FROM pgr_drivingDistance(
                 'SELECT id, source, target, cost FROM edge_table',
                 7, 1.5, false, false
         )
       ),
dd_points AS(
SELECT id, x, y
     FROM vertex_table w, DD d
     WHERE w.id <http://w.id> = d.node
     )
SELECT pgr_alphaShape('SELECT * FROM dd_points');


doesn't work...

ERROR:  relation "dd_points" does not exist


I understand why this doesn't work, but I'm not sure how to work around.


On 06/21/2013 04:39 PM, Stephen Mather wrote:
> Ok so it get's interesting trying to use embed one function within 
> another, for example calculating driving distance and wrapping with 
> alpha shape.
>
> This is as far as I've gotten:
>
>
>
>
> On 06/21/2013 04:07 PM, Stephen Mather wrote:
>> Hi All,
>>
>> Having a great time with 2.0-develop.  Question on 
>> pgr_drivingDistance.  I added geometry to the test dataset and wrote 
>> the following query to return all points within driving distance:
>>
>> WITH DD AS (
>> SELECT seq, id1 AS node, cost
>>         FROM pgr_drivingDistance(
>>                 'SELECT id, source, target, cost FROM edge_table',
>>                 7, 1.5, false, false
>>         )
>>         )
>>
>> SELECT ST_AsText(the_geom)
>>     FROM vertex_table w, DD d
>>     WHERE w.id <http://w.id> = d.node
>>     ;
>>
>> A) Am I correct in my usage of this?
>> B) Am I correct in assuming there is no way (at this time) to return 
>> subsets of lines, similar to TSP?
>>
>> Best,
>> Steve
>>
>>
>> _______________________________________________
>> pgrouting-dev mailing list
>> pgrouting-dev at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/pgrouting-dev
>

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