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| {{Upravit}} | | {{freegiswiki|PgRouting}} |
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| [http://pgrouting.postlbs.org pgRouting] je rozšíření pro [[PostGIS]] určené pro síťové analýzy.
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| * Vyhledání nejkratší cesty
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| * Problém obchodního cestujícího
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| * Dojezdová vzdálenost
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| == Poznámky ==
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| Nahrání funkcí pgRouting to existující databáze.
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| psql pgis_student -f /usr/share/postlbs/routing_core.sql
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| psql pgis_student -f /usr/share/postlbs/routing_core_wrappers.sql
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| psql pgis_student -f /usr/share/postlbs/routing_topology.sql
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| <!-- psql pgis_student -f /usr/share/postlbs/matching.sql -->
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| == Nahrání testovacích dat ==
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| Testovací data jsou dostupná z
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| svn checkout http://pgrouting.postlbs.org/svn/pgrouting/branches/workshop/FOSS4G2008/ workshop
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| Nahrajeme testovací data.
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| cd workshop
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| psql pgis_student -f Data/ways_without_topology.sql
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| <pre>
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| \d ways
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| Table "public.ways"
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| Column | Type | Modifiers
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| ----------+------------------+-----------
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| gid | integer | not null
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| length | double precision |
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| name | character(200) |
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| the_geom | geometry |
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| Indexes:
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| "ways_pkey" PRIMARY KEY, btree (gid)
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| Check constraints:
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| "enforce_dims_the_geom" CHECK (ndims(the_geom) = 2)
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| "enforce_geotype_the_geom" CHECK (geometrytype(the_geom) = 'MULTILINESTRING'::text OR the_geom IS NULL)
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| "enforce_srid_the_geom" CHECK (srid(the_geom) = 4326)
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| </pre>
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| Dále vytvoříme topologii sítě.
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| <source lang="sql">
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| ALTER TABLE ways ADD COLUMN source integer;
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| ALTER TABLE ways ADD COLUMN target integer;
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| SELECT assign_vertex_id('ways', 0.00001, 'the_geom', 'gid');
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| </source>
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| Doplníme indexy.
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| <source lang="sql">
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| CREATE INDEX source_idx ON ways(source);
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| CREATE INDEX target_idx ON ways(target);
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| CREATE INDEX geom_idx ON ways USING GIST(the_geom GIST_GEOMETRY_OPS);
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| </source>
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| <pre>
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| \d ways
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| Table "public.ways"
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| Column | Type | Modifiers
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| ----------+------------------+-----------
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| gid | integer | not null
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| length | double precision |
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| name | character(200) |
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| the_geom | geometry |
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| source | integer |
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| target | integer |
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| Indexes:
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| "ways_pkey" PRIMARY KEY, btree (gid)
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| "geom_idx" gist (the_geom)
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| "source_idx" btree (source)
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| "target_idx" btree (target)
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| Check constraints:
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| "enforce_dims_the_geom" CHECK (ndims(the_geom) = 2)
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| "enforce_geotype_the_geom" CHECK (geometrytype(the_geom) = 'MULTILINESTRING'::text OR the_geom IS NULL)
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| "enforce_srid_the_geom" CHECK (srid(the_geom) = 4326)
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| </pre>
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| == Vyhledání nejkratší cesty (Dijkstra) ==
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| == Externí odkazy ==
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| * [http://pgrouting.postlbs.org pgRouting]
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| {{Databáze}}
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| {{GIS}}
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| {{GFOSS}}
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