wkt syntax (howto)

Geometry types and their text representations

Geometry type	WKT representation	Comment
point	POINT EMPTY	empty point
point	POINT ( 10.05 10.28 )	point
point	POINT Z( 10.05 10.28 2.51 )	point with Z coordinate
point	POINT M( 10.05 10.28 4.72 )	point with M coordinate
point	POINT ZM( 10.05 10.28 2.51 4.72 )	point with Z coordinate and M coordinate
linestring	LINESTRING EMPTY	empty linestring
polygon	POLYGON (( 10 10, 10 20,20 20, 20 15, 10 10))	polygon
multipoint	MULTIPOINT Z(10 10 2, 20 20 3)	multipoint with Z coordinates
multilinestring	MULTILINESTRING M(( 310 30 1, 40 30 20, 50 20 10 )( 10 10 0, 20 20 1))	multilinestring with M coordinates
multipolygon	MULTIPOLYGON ZM((( 1 1 1 1, 1 2 3 4, 2 2 5 6, 2 1 7 8, 1 1 1 1 )))	multipolygon with Z coordinates and M coordinates

Advanced drawing in chameleon

Today i noticed the guys at http://www.uwaterloo.ca have been working on some really advanced javascript drawing techniques for chameleon. They used walter zorn's drawing library to create dynamic circle and polyline drawing tools.

opensource gis desktop clients

Recently some opensource (free) desktop GIS clients came to my attention.

• uDig (http://udig.refractions.net/confluence/display/UDIG/Home ) is a java-eclipse based environment for viewing maps (.shp,tiff,wms,wfs,postgis). The eclipse environment offers you ease of configuration to build your own gis-cleint.
• gvSig is a free multi langual gis-client in java by a spanish firm (wms, wfs). (http://www.gvsig.gva.es )

Basic clients

openEv is a basic gis-viewer by frank warmerdam (http://fwtools.maptools.org/ )

development environments

Lots of groups offer platfoms in which you can easily build your own desktop gis client.

http://www.geovistastudio.psu.edu

http://www.vividsolutions.com/jts/jtshome.htm

http://openmap.bbn.com

Free clients
- the guys at http://www.tatukgis.com created a Delphi.net environment in wich you can build your own viewer with a few clicks. But they also offer e simple viewer for free. Tatuk manages to put all gis-functionality in just a tiny 10mb application.

soon to come
- At http://fmaps.sourceforge.net they are coding to bring a decent gis-client to the linux-platform. They use postgis to store data.