Geometries for Python

Update (2008-01-21)

See http://pypi.python.org/pypi/Shapely/1.0

Update: http://sgillies.net/blog/429/geometries-for-python-update/

The next release of PCL will include two new components: PCL-Spatial, and PCL-Data, industrial-strength geometries and an agile feature model for Python programmers. I'm going to write about geometries today, and about the feature model in a day or two.

PCL-Spatial is a Python package that wraps and extends GEOS. The Geometry Engine - Open Source is a C++ port of Vivid Solutions' Java Topology Suite, and is the open source C/C++ library for spatial predicates and geometric operations. It's used in GDAL, MapServer, and MapGuide Open Source, to name a few applications, and Safe Software and Autodesk are funding work that will eventually produce a GEOS 3.0 release.

Why not use one of the existing Python geometry modules? Good question. The short answer is that none of them are quite good enough. Everything out there right now comes up a bit short in capability, usability, or portability.

Geospatial on NPR

Interesting story this morning on NPR's Weekend Edition about coordinate reference systems and emergency response. Dan Charles did a nice job explaining how useful the National Grid (Hey, what do you know: Plone) is to helicopter-borne National Guardsmen, and how little use it is to someone driving a squad car or ambulance on network of streets. The conventional street address is just a better match for the topology.

Comments

Re: Geospatial on NPR

Author: Mark Whitney

"and how little use it is to someone driving a squad car or ambulance on network of streets" What is this part of Sean's statement based upon? Given the lack of implementation, how would anyone know? Given it's very valuable use to many thousands responding to disaster areas, and at least one percent of USA fire departments pre-911 for everyday use (same FD frequency as individual versions lat/long).... Similar system in Great Britain widespread..., is it "how little use" or is it "the extreme lack of leadership in USA government regarding a universal map reference has thus far kept it's usefulness from being fully realized, therefore recognized or even remotely known"?

Re: Geospatial on NPR

Author: Sean

In a automobile, you are pretty much constrained to one dimension, and people still think in terms of "turn right on sycamore, left on oak, ..." because it really works. I'm not saying the national grid isn't useful, just that it doesn't help automobile navigation.

Re: Geospatial on NPR

Author: Mark Whitney

Just saw my first TV commercial where the nav system in the vehicle was voice controlled. I'm driving down the road non-disaster/non-emergency, all street signs are present and accounted for, a friend calls me to invite me to a picnic using “0044 9732” (and just to be high-tech a few years from now..., nav system automatically computes for nearest grid/prompts for 100k id if different, then routes...), just repeating that simple 10 meter geoaddress..., with no worries re. street number and accuracy of geocodes, especially in rural areas, nor street names, multiple same city…, avenue, way, circle, route, hwy.... Of course, my friend could include a place name, street address... in voice or other commo should needs be, but with grid first communications, the future of location service devices, this would become a valuable advisory….. Mark "In a automobile, you are pretty much constrained to one dimension, and people still think in terms of "turn right on sycamore, left on oak, ..." because it really works. I'm not saying the national grid isn't useful, just that it doesn't help automobile navigation."

PrimaGIS 0.5.1

Kai has just released PrimaGIS 0.5.1, which requires an upgrade to ZCO 0.7.1. Important changes in this release include:

  • Use of the ZCO MapRendererTool (portal_gis)

  • Upgrade of MochiKit library to version 1.2

  • Integration of Tim Schaub's Javascript scalebar.

  • Alpha blending for the background of the zoom-in box (thanks jlivni)

Dublin Code Sprint

Nevermind the ESRI Developer Summit; the place to be next month is Dublin, Ireland, for the first ever Python Cartographic Library and PrimaGIS code sprint. It's hosted by OpenApp, and scheduled for 8-10 March. The current goals are to port PrimaGIS to Zope3, improve the Python Cartographic Library, and bring key new programmers up to speed on the projects. Goals may be modified as interest warrants. We have 4 already (Con Hennessy, Michael Kerrin, Kai Hanninen, and me) and have room for up to 3 others. Details, including contact information, are at

http://trac.gispython.org/projects/zope/wiki/Sprints

I cannot thank OpenApp enough for their support, this is going to be great!

Open Source Geospatial Foundation

As expected, the meeting was a success. I am really pleased with the interim Board of Directors. Gary Lang has impressed me, and I've already met Arnulf Christl (of MapBender), Markus Neteler (GRASS), Frank Warmerdam (GDAL), and Chris Holmes (GeoServer). I trust all of them to get things off to a good start.

Incubating Everyone

The principals of the emerging geospatial software foundation have discussed adopting the concept of a project incubator from the Apache Software Foundation. New projects would be developed in the incubator framework until they had demonstrated viability, and then would be promoted to full foundation project status. The ASF makes no technical requirements, and concerns itself only with the vigor of projects, meritocracy, and clarity of copyright and intellectual property issues.

MapServer and MapGuide

According to the All Points Blog, Autodesk's new open source licensed successor to MapGuide will be named ... MapGuide. I've been trying to make the point that project name churn doesn't help the foundation cause at all, and I'm happy to see that all parties have arrived at the same conclusion. MapServer remains MapServer, MapGuide remains MapGuide, and the projects move on to new business. I'll be suprised if we don't now see a stampede towards MapTools as a foundation name.