[postgis-users] postgis topology

[Ludovic Granjon]

The image

Le 15/01/2014 14:35, Ludovic Granjon a écrit :
> Thanks all, so
>
> if I try like Sandro said :
>
> UPDATE ec SET geom = ST_SnapToGrid(geom, 1);
> UPDATE ec SET topo_geom = toTopoGeom(geom, 'ec_topo', 1, 1.0);
>
> I have this error :
> SQL/MM Spatial exception - curve not simple
>
> If i increase tolerance parameter, I have :
> ERREUR: SQL/MM Spatial exception - point not on edge
>
> With Rémi's solution :
>
> UPDATE ec SET topo_geom = rc_totopogeomwithouterrors(geom, 'ec_topo', 
> 1, 1.0);
>
> It works with a lot (76) of NOTICE:  this geometry can't be converted 
> to topogeom :
> but other geometry worked
>
> so it's better
>
> Now, I have to know why some geometry doesn't work
>
> Maybe I have to explain more what I'm trying to do
>
> My data overlap and there are not clean. Sometimes polygon should have 
> jointly vertex but it's not the case. (I join a image)
>
> I want to snap when the distance is smaller than tolerance and 
> intersect polygon when they overlap.
>
> Do you think that use topology is the best way to do that ?
>
> Thanks a lot
>
> regards
>
> Ludovic
>
>
>
>
>
> Le 15/01/2014 13:49, Rémi Cura a écrit :
>> -- Function: public.rc_totopogeomwithouterrors(geometry, character 
>> varying, integer, double precision)
>>
>> -- DROP FUNCTION public.rc_totopogeomwithouterrors(geometry, 
>> character varying, integer, double precision);
>>
>> CREATE OR REPLACE FUNCTION public.rc_totopogeomwithouterrors(ageom 
>> geometry, atopology character varying, alayer integer, atolerance 
>> double precision DEFAULT 0)
>>   RETURNS topogeometry AS
>> $BODY$
>> DECLARE
>>   layer_info RECORD;
>>   topology_info RECORD;
>>   rec RECORD;
>>   tg topology.TopoGeometry;
>>   elems topology.TopoElementArray = '{{0,0}}';
>>   sql TEXT;
>>   typ TEXT;
>>   tolerance FLOAT8;
>> BEGIN
>>
>> raise notice 'ageom : %',ST_AsText(ageom);
>>   -- Get topology information
>>   BEGIN
>>     SELECT *
>>     FROM topology.topology
>>       INTO STRICT topology_info WHERE name = atopology;
>>   EXCEPTION
>>     WHEN NO_DATA_FOUND THEN
>>       RAISE EXCEPTION 'No topology with name "%" in topology.topology',
>>         atopology;
>>   END;
>>
>>   -- Get tolerance, if 0 was given
>>   tolerance := COALESCE( NULLIF(atolerance, 0), 
>> topology._st_mintolerance(atopology, ageom) );
>>
>>   -- Get layer information
>>   BEGIN
>>     SELECT *, CASE
>>       WHEN feature_type = 1 THEN 'puntal'
>>       WHEN feature_type = 2 THEN 'lineal'
>>       WHEN feature_type = 3 THEN 'areal'
>>       WHEN feature_type = 4 THEN 'mixed'
>>       ELSE 'unexpected_'||feature_type
>>       END as typename
>>     FROM topology.layer l
>>       INTO STRICT layer_info
>>       WHERE l.layer_id = alayer
>>       AND l.topology_id = topology_info.id <http://topology_info.id>;
>>   EXCEPTION
>>     WHEN NO_DATA_FOUND THEN
>>       RAISE EXCEPTION 'No layer with id "%" in topology "%"',
>>         alayer, atopology;
>>   END;
>>
>>   -- Can't convert to a hierarchical topogeometry
>>   IF layer_info.level > 0 THEN
>>       RAISE EXCEPTION 'Layer "%" of topology "%" is hierarchical, 
>> cannot convert to it.',
>>         alayer, atopology;
>>   END IF;
>>
>>
>>   --
>>   -- Check type compatibility and create empty TopoGeometry
>>   -- 1:puntal, 2:lineal, 3:areal, 4:collection
>>   --
>>   typ = geometrytype(ageom);
>>   IF typ = 'GEOMETRYCOLLECTION' THEN
>>     --  A collection can only go collection layer
>>     IF layer_info.feature_type != 4 THEN
>>       RAISE EXCEPTION
>>         'Layer "%" of topology "%" is %, cannot hold a collection 
>> feature.',
>>         layer_info.layer_id, topology_info.name 
>> <http://topology_info.name>, layer_info.typename;
>>     END IF;
>>     tg := topology.CreateTopoGeom(atopology, 4, alayer);
>>   ELSIF typ = 'POINT' OR typ = 'MULTIPOINT' THEN -- puntal
>>     --  A point can go in puntal or collection layer
>>     IF layer_info.feature_type != 4 and layer_info.feature_type != 1 THEN
>>       RAISE EXCEPTION
>>         'Layer "%" of topology "%" is %, cannot hold a puntal feature.',
>>         layer_info.layer_id, topology_info.name 
>> <http://topology_info.name>, layer_info.typename;
>>     END IF;
>>     tg := topology.CreateTopoGeom(atopology, 1, alayer);
>>   ELSIF typ = 'LINESTRING' or typ = 'MULTILINESTRING' THEN -- lineal
>>     --  A line can go in lineal or collection layer
>>     IF layer_info.feature_type != 4 and layer_info.feature_type != 2 THEN
>>       RAISE EXCEPTION
>>         'Layer "%" of topology "%" is %, cannot hold a lineal feature.',
>>         layer_info.layer_id, topology_info.name 
>> <http://topology_info.name>, layer_info.typename;
>>     END IF;
>>     tg := topology.CreateTopoGeom(atopology, 2, alayer);
>>   ELSIF typ = 'POLYGON' OR typ = 'MULTIPOLYGON' THEN -- areal
>>     --  An area can go in areal or collection layer
>>     IF layer_info.feature_type != 4 and layer_info.feature_type != 3 THEN
>>       RAISE EXCEPTION
>>         'Layer "%" of topology "%" is %, cannot hold an areal feature.',
>>         layer_info.layer_id, topology_info.name 
>> <http://topology_info.name>, layer_info.typename;
>>     END IF;
>>     tg := topology.CreateTopoGeom(atopology, 3, alayer);
>>   ELSE
>>       -- Should never happen
>>       RAISE EXCEPTION
>>         'Unsupported feature type %', typ;
>>   END IF;
>>
>>   -- Now that we have a topogeometry, we loop over distinct components
>>   -- and add them to the definition of it. We add them as soon
>>   -- as possible so that each element can further edit the
>>   -- definition by splitting
>>
>> --modified to catch errors:
>> BEGIN
>>
>>   FOR rec IN SELECT DISTINCT id(tg), alayer as lyr,-- geom,
>>     CASE WHEN ST_Dimension(geom) = 0 THEN 1
>>          WHEN ST_Dimension(geom) = 1 THEN 2
>>          WHEN ST_Dimension(geom) = 2 THEN 3
>>     END as type,
>>     CASE WHEN ST_Dimension(geom) = 0 THEN
>>            topology.topogeo_addPoint(atopology, geom, tolerance)
>>          WHEN ST_Dimension(geom) = 1 THEN
>>            topology.topogeo_addLineString(atopology, geom, tolerance)
>>          WHEN ST_Dimension(geom) = 2 THEN
>>            topology.topogeo_addPolygon(atopology, geom, tolerance)
>>     END as primitive
>>     FROM (SELECT (ST_Dump(ageom)).geom) as f
>>     WHERE NOT ST_IsEmpty(geom)
>>   LOOP
>>   --raise notice 'coucou, tg : %, geom %',rec.id <http://rec.id>, 
>> ST_AsText(rec.geom);
>>     -- TODO: consider use a single INSERT statement for the whole thing
>>     sql := 'INSERT INTO ' || quote_ident(atopology)
>>         || '.relation(topogeo_id, layer_id, element_type, element_id) 
>> VALUES ('
>>         || rec.id <http://rec.id> || ',' || rec.lyr || ',' || rec.type
>>         || ',' || rec.primitive || ')';
>>     EXECUTE sql;
>>   END LOOP;
>>
>>   RETURN tg;
>> EXCEPTION
>>     WHEN SQLSTATE 'P0001' THEN
>>         RAISE NOTICE 'this geometry can''t be converted to topogeom : %
>> doing nothing',ageom;
>> RETURN NULL;
>> END;
>> END
>> $BODY$
>>   LANGUAGE plpgsql VOLATILE STRICT
>>   COST 100;
>> ALTER FUNCTION public.rc_totopogeomwithouterrors(geometry, character 
>> varying, integer, double precision)
>>   OWNER TO postgres;
>
>
>
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