Regina Obe has just announced that PostGIS in Action book website launched. It is http://postgis.us
Posts Tagged ‘postgis’
postgis dot us
Sunday, February 7th, 2010How PostGIS can help SQL Server users?
Wednesday, February 3rd, 2010I may be a gonzo or it’s just that today I didn’t have my notorious 4th coffee in my favourite Winnie The Pooh cup I got from Pantera on our 14th (or 15th?) anniversary we celebrated a month ago, so…
Apparently, there are situations in which PostGIS could be an affordable anti-GML vaccine jab. It seems there is a potential market for PostGIS to conquer. Perhaps it wouldn’t be estimated as profitable as the H1N1 but who knows what will happen if no one takes a brave stand and stop GML designers! Here I’d eagerly conclude with one of the famous Scottish sentences :-)
Back to the subject matter. Today, I spotted an interesting question on the StackOverflow archives: Is it possible to export spatial data from Sql Server 2008 in gml2 format?. Natively? No, there is no such solution. Presumably, Microsoft thinks forward and thinks GML 2 is a legacy standard. Fair enough, someone has to draw a line between prehistoric and modern, somewhere. Why Microsoft? Again?
Facing such a tremendous suffer Microsoft exposed SQL Server users to, I suggested to visit the “underworld” for a while and hire PostGIS to do the dirty job.
Paraphrasing Andrei Alexandrescu’s, hysterically famous recently, sentence: SQL Server should go!.
PostGIS 1.5.0 will require GEOS 3.1.0+
Friday, January 15th, 2010
PostGirls and PostBoys, be prepared!
The upcoming release of PostGIS 1.5.0 (available as beta1 beta2) will require GEOS in version 3.1.0 or later.
The beta1 testing results suggested to bump the minimum GEOS version to 3.1.0. The GEOS requirement issue was one of the heavily discussed topics on the postgis-devel this month.
The PostGIS team is going to give GEOS a nice present for its 10th round month birthday.
PostGIS explains DE-9IM
Sunday, December 6th, 2009I am happy I belong to the hordes of PostGIS users. Recently I asked for a very small addition to the PostGIS manual that will explain the three basic terms of the geospatial geometry: interior, boundary and exterior.
Kevin Neufeld delivered a very well written chapter about Dimensionally Extended 9 Intersection Model (DE-9IM) with series of excellent visualisations of the non-trivial mathematics.
Moreover, Kevin started completing the PostGIS Functions Reference with visual presentation of geometric problems together with SQL commands using various PostGIS functions that can be applied to solve particular situations. For example, what does the ST_Buffer function, how boolean predicates like ST_Contains check spatial relation of two geometries or what’s the difference between ST_Difference and ST_SymDifference.
Clearly, I’ve got way way more than I asked for or I expected. On behalf of myself and users who are about to start their adventure with PostGIS, I’d like to give big kudos to Kevin for this fantastic work!
Together with the recently documented PostgreSQL PostGIS Types and Function Support Matrix, PostGIS team is making abrupt manual a pleasant reading book.
By the way, here is a bunch of references about DE-9IM I found very useful myself:
- Dimensionally Extended Nine-Intersection Model (DE-9IM) by Christian Strobl
- Encyclopedia of GIS by Hui Xiong, page 242
PostGIS Function Support Matrix
Thursday, December 3rd, 2009Regina crafted matrix of functions available in upcoming PostGIS 1.5. Currently, PostGIS 1.5 is available from trunk in the Subversion repository.
The PostGIS 1.5 documentation is available under the manual-svn node and here is the PostGIS Function Support Matrix.
Regina, great job!
By the way, there is an interesting problem with check marks. does anyone know how to define check marks based on Unicode and make them visible in IE8?
ST_PostGIS(EMPTY) => ?
Tuesday, October 6th, 2009 Having problems with understanding semantic of EMPTY geometry?
Paul Ramsey has started wrapping up a proper article on PostGIS Wiki explaining most of the issues related to understanding of emptiness of geometries bothering the community of PostGIS users, and OGC standards users in general.
Check it like it’s hot DevWikiEmptyGeometry. Thanks Paul!
PostGIS In Action
Thursday, May 7th, 2009It really must be very hot and fresh news, so the virtual devil spirit of social networking hasn’t fished it out yet and also Google (check this if you haven’t heard yet about this local family company) lists less than 15 pages.
PostGIS provides over 300 spatial operators, spatial functions, spatial data types and spatial indexing enhancements. If you add to the mix the complimentary features that PostgreSQL and other PostgreSQL related projects provide, then you’ve got one jam-packed powerhouse at your disposal well suited for hardcore work as well as a valuable training tool for spatial concepts.
Three words: PostGIS In Action. The first book about PostGIS spatial database being written by Regina O. Obe and Leo S. Hsu with release planned for the beginning of 2010. First chapter of the book has been published and is freely available as PDF file through the Manning Early Access Program. Chapter two and three are also available for MAEP subscribers.
Next to the early access, another cool thing about the way Manning Publications release their books is possibility to comment chapters and discuss with authors directly through Manning Sandbox forums. There is no exception for the PostGIS in Action :-)
Update 2009-05-08T23:08:21+00:00: The book official announcement has been posted on postgis-devel and postgresqlonline.com.
I’m looking forward to grab the book!
Pierre, check the TOC for chapter thirteen. Cool, isn’t it?
