GRASS Vector Layers - Revision history

Neteler: /* Introduction */

2011-12-07T00:36:51Z

Introduction

← Older revision		Revision as of 00:36, 7 December 2011
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	Grass documentation provides basic information about vector attribute management,		Grass documentation provides basic information about vector attribute management,
	categories of vector features and vector layers.		categories of vector features and vector layers.
	<ref>http://grass.osgeo.org/~~grass63~~/manuals/~~html63_user~~/vectorintro.html</ref>		<ref>http://grass.osgeo.org/grass64/manuals/html64_user/vectorintro.html</ref>

	The aim of this tutorial is to show how to create, manipulate and		The aim of this tutorial is to show how to create, manipulate and

2011-12-07T00:36:29Z

References

2008-08-20T22:52:04Z

← Older revision		Revision as of 22:52, 20 August 2008
(No difference)

2008-08-19T23:44:08Z

Road Network Data

← Older revision		Revision as of 23:44, 19 August 2008
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	$ g.remove vect=tmpmap		$ g.remove vect=tmpmap

	Vector map '''roads''' is connected to DBF file, which is no longer required~~. Therefore~~		Vector map '''roads''' is connected to DBF file, which is no longer required,
	it has to be removed		it has to be removed using command

	$ v.db.droptable -f roads		$ v.db.droptable -f roads

2008-08-19T23:41:09Z

Appendix: Creating Tutorial's Road Network and Routes Data

← Older revision		Revision as of 23:41, 19 August 2008
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	== Appendix: Creating Tutorial's Road Network and Routes Data ==		== Appendix: Creating Tutorial's Road Network and Routes Data ==
	Sample data for this tutorial were extracted from Spearfish data.		Sample data for this tutorial were extracted from Spearfish data.
	As it was quite interesting excersise, ~~below~~ detailed information		As it was quite interesting excersise, detailed information
	~~is provided~~ describing the process.		describing the process is provided below.

	=== Road Network Data ===		=== Road Network Data ===

2008-08-19T23:39:49Z

Creating Layers

← Older revision		Revision as of 23:39, 19 August 2008
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	=== Creating Layers ===		=== Creating Layers ===
	Vector map '''roads''' has one layer of categories and it is not connected to any database table.		Vector map '''roads''' provided with sample data has one layer of categories and
	This can be checked with commands		it is not connected to any database table. This can be checked with commands

	$ v.db.connect -p map=roads		$ v.db.connect -p map=roads
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	all 825 1 825		all 825 1 825

			To connect vector map with two layers of data, vector categories
			have to be populated into these layers using following commands


	~~Vector categories have to be populated into two layers~~
	~~(or more if required)~~
	$ v.category --o input=roads layer=2 output=tmprn		$ v.category --o input=roads layer=2 output=tmprn
	$ g.remove vect=roads		$ g.remove vect=roads

2008-08-19T23:37:15Z

Sample Data

← Older revision		Revision as of 23:37, 19 August 2008
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	== Creating Grass Vector Layers ==		== Creating Grass Vector Layers ==
	=== Sample Data ===		=== Sample Data ===
	Sample data can be downloaded ~~from [[Media~~:gvl-0.1.~~tar~~.~~gz]]~~.		Sample data can be downloaded using one of the links
			* http://entropy.echelon.pl/wrobell/grass/gvl-0.1.zip
			* http://wrobell.it-zone.org/grass/gvl-0.1.zip

	The archive contains basic relational database and Grass		The archive contains basic relational database and Grass
	data based on Spearfish data		data based on Spearfish data

2008-08-19T23:28:39Z

Sample Data

← Older revision		Revision as of 23:28, 19 August 2008
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	== Creating Grass Vector Layers ==		== Creating Grass Vector Layers ==
	=== Sample Data ===		=== Sample Data ===
	~~File~~ [[Media:gvl-0.1.tar.gz]] ~~attached to this tutorial~~ contains Grass data based on Spearfish		Sample data can be downloaded from [[Media:gvl-0.1.tar.gz]].
	data ~~and basic relational database~~		The archive contains basic relational database and Grass
	* road network Grass vector map '''roads'''		data based on Spearfish data
	* '''gvl.sqlite''' file is SQLite relational database file~~, which has~~ tables and view described above		* '''gvl.sqlite''' file is SQLite relational database file with tables and view described above
			* vector map '''roads''' containing road network map data

	~~Unzip the file with~~ sample data~~, enter its directory~~ and start Grass		To start processing sample data unpack the archive and start Grass
			within PERMANENT location

	$ unzip gvl-0.1.zip		$ unzip gvl-0.1.zip

2008-06-08T08:33:56Z

Datamodel Discussion

← Older revision		Revision as of 08:33, 8 June 2008
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	realized with a SQL view, i.e.		realized with a SQL view, i.e.
	create view route_rn as		create view route_rn as
	select rn.cat as cat, rn.id as id, r.route_id as route_id		select rn.cat as cat,
	from route r left join road_network rn on r.rn_id = rn.id;		rn.id as id,
			r.route_id as route_id
			from route r
			left join road_network rn on r.rn_id = rn.id;

	Above tables and view allow to provide road network and driven routes information. They		Above tables and view allow to provide road network and driven routes information. They

2008-06-08T08:32:22Z

Datamodel Discussion

← Older revision		Revision as of 08:32, 8 June 2008
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	Routes table shall consist of		Routes table shall consist of
	* route identifier		* route identifier
	* id of road segment driven on a route, which ~~reference~~ road segment id in road network table		* id of road segment driven on a route, which references road segment id in road network table

	Routes table also has to provide vector category information. This can be		Routes table also has to provide vector category information. This can be