GeoAr OpenLazlo WMS/WFS Client

I finally had a chance to play around with a new WMS/WFS client called GeoAr after the author, Jose contacted me last week. This was a run on to my previous article on GIS OpenLazlo development and contains similar functionality to the other client GeaBios, but lacks a lot of the more advaned features.

There is a demo available which uses the standard demis WMS service if anyone wants to take a look and give any support.

Overall it does what it says it does but i wouldnt be using this at the moment for a quick-deployment option as installation of Eclipse/OpenLazlo is required. A Javascript API for configuring services would certainly make this client a better option

Geabios for the win though, i can’t wait until the HTML output option for Lazlo is released

WALIS 2006 Conference program available

Ok, so this is a little plug but i’m putting the invitation out there for attending WALIS 2006 in Perth (Australia) September 13-15 at the Perth Convention Centre.

walis.JPG

The program has just been released and contains a plethora of interesting workshops and presentations with the conference theme being “Unearth your Spatial Potential”.

Speakers of note include Jerome Shephard (LINZ), Pedro Harris & David Hayward (NSW Lands), Simon Cox & Rob Woodcock (CSIRO), Doug Nebert (FGDC), Chris Holcroft (Cadcorp), Andreas Mathus (University of Munich/Latlon?) and the usual “celebrities” from ESRI, Mapinfo and Intergraph around Australia. I may also be presenting at one of the dataservices slots on WFS integration techniques so that alone must be good enough incentive!

So if you cant afford the $$ to get to Switzerland for the FOSS4G2006 conference this is your chance.

Check out the forum webpage or contact WALIS and they’ll be more than happy to answer any questions.

Pencil it in! It really is a great vendor-neutral event which seem to be few and far between nowadays. We are also looking to hold a separate social event for those interested in open standards, open source GIS. Stay tuned

PGdijkstra Routing performance

I have gotten a surprising amount of questions since i posted my routing articles using Cartoweb’s pgdijkstra PostGIS pl/sql functions. A lot have focused around the speed of the routing calculations, especially in comparison with commercial offerings.

Disclaimer: This should only aid in you decision making. I definately would not consider using pgdjikstra to replace emergency vehicles routing and travelling salesmen type problems. Considerable work would need to be added to flesh out commonly requested features such as turn by turn navigation

Alright, lets see how we went …

Sample dataset: 57k vertices, 44k nodes

Machine specs: P4 Celeron M 2.6ghz Laptop, 512mb RAM, PostgreSQL 8.1

Sample queries are using the following function,

SELECT astext(the_geom) FROM shortest_path_as_geometry(‘roadstable’, startnode, endnode)

uery

Key

From

To

Path Size

(coord pairs)

Query Time

1

219102

181359

792

984.056 ms

2

216366

179845

738

1289.002 ms

3

229280

188416

586

871.655 ms

4

205276

197586

660

1421.800 ms

5

229280

179038

941

2180.597 ms

6

209203

206037

491

1101.798 ms

7

203982

193450

208

755.187 ms

Routing geometry
Click to enlarge!

Considering my laptop is definately not the best benchmark machine, I can only assume that deployment on a proper server environment would result in a significant performance increase across the board.

Interesting stuff! Head over to cartoweb.org to give Sylvain and his crew any feedback or bugs. I havent checked lately but i’m sure the CVS version have had some improvements.

OGC vs GeoRSS

Ok so the title is a bit dramatic but Howard Butler has written an excellent article over at hobu.biz to give his point of view over OGC‘s “smash and grab” on the developing GeoRSS standard.

Too many great quotes to agree with, but this one particularly hit a chord with myself,

The implementation of OGC specs for the large GIS vendors historically has been uneven at best, with bits and bytes dangling about — giving the hope and appearance of interoperability but ultimately failing to deliver on the promise. In fact, in many ways it has been the small vendors and open source implementations like MapServer and GeoServer that have carried the torch of true OGC interoperability.

I must admit i have been largely on the sidelines reading the eogeo lists but i am certainly intrigued by OGC’s interest in GeoRSS given its use would benefit largely individuals and web development products – certainly a far cry from OGC’s GIS-centric member list.

From Allan Doyle’s response:

I believe it’s in the best interests of keeping GeoRSS open and
available to everyone to for us to keep it under a Creative Commons
license.

If you read one thing in the GIS blogosphere this would be it. Come on hobu, open up comments!