Sean Gillies Blog

I've been saving this news for my 200th post. My new position is the software developer for UNC-CH's Ancient World Mapping Center, and I'll be working on the AWMC's Pleiades project. Pleiades (the daughters of Atlas) continues the work of the Classical Atlas Project. I'll be building a system -- and helping to build a community -- to update the Barrington Atlas of the Greek and Roman World.

Pleiades will be built using PostGIS, Python, and Plone. Our software will be open source, and developed for reuse by similar future projects in the Digital Humanities. I'll be using many of my favorite tools, and applying them to a completely new domain. Pleiades will be a driver of new developments in the Python Cartographic Library and PrimaGIS, and help steer the Plone community in the right geospatial directions. On top of all of this goodness, I'm going to get to learn a ton about Greek and Roman history, epigraphy, and Unicode. Members of the steering committee are keen to see Pleiades data in Google Earth or World Wind, and this will be a new and interesting direction for me as well. It's a dream job, and I'm still pinching myself.

If you're interested in a historian's take on Wikipedia and the impact of the Wikipedia process on scholarship, check out Roy Rosenzweig's excellent essay: Can History be Open Source? (via The Stoa Consortium). It was the talk of the History blogosphere around the middle of June after appearing in The Journal of American History, but I missed it due to my newness on the scene and preparation for our first Pleiades meeting. The essay is enormously relevant to the Pleiades project, and we'll be disseminating it to all our potential users.

After a brief history of Wikipedia and an analysis of its accuracy (pretty good) and prose (generally mushy), Rosenzweig considers what a Wikipedia-like peer production process might achieve with the participation of professional historians:

If the Internet and the notion of commons-based peer production provide intriguing opportunities for mobilizing volunteer historical enthusiasm to produce a massive digital archive, what about mobilizing and coordinating the work of professional historians in that fashion? That so much professional historical work already relies on volunteer labor -- the peer review of journal articles, the staffing of conference program committees -- suggests that professionals are willing to give up significant amounts of their time to advance the historical enterprise. But are they also willing to take the further step of abandoning individual credit and individual ownership of intellectual property as do Wikipedia authors?

The AWMC wants to preserve individual credit. Absolutely. But it's still going to be tricky. We'll need a lot of finesse to deal with perceptions about the big step.

Slick! You better believe I'll be trying out the SIMILE Timeline for the Pleiades site. I welcome the support for JSON because every time someone creates a new XML language, God kills a kitten. Via Ned Batchelder.

In my 200th post I wrote about the Pleiades project and our intent to be geospatial leaders for the Plone community and the digital humanities. Release early, release often is a part of the philosophy that Pleiades is porting from the open source software movement. Two months into the project, we're releasing a couple of simple and useful products for Plone: a geocoder, PleiadesGeocoder, and a map, PleiadesOpenLayers.

I was sending an email to the FRUGOS list about data processing with GDAL and OGR, and wrote that there is low-hanging fruit in the form of an open source graphical data processing model builder. One attendee of last week's meetup said that the ArcGIS model builder was the only thing he couldn't do without. I met another open source GIS user this summer who also expressed an appreciation for the model builder despite the overall awkwardness of the geoprocessing tool. People love GDAL and OGR. People love graphical modeling. I think we can have these and the benefits of open source as well.

For the Pleiades project we are authoring custom Plone content types using ArchGenXML. We design the content package and its classes using ArgoUML class diagrams. ArchGenXML parses the exported XMI file and creates Plone Archetype based classes -- Python code and scaffolding. ArchGenXML is a remarkable product, allowing someone with no specific Python skill to produce functional Python packages for use in Plone. I believe it would make an excellent starting point for a graphical data processing modeler:

1. Create a activity diagram in ArgoUML.
2. Export to XMI.
3. Parse, adapting the ArchGenXML code, and generate Python modules using gdal.py and ogr.py to execute the diagrammed processes.

The result: a highly portable, visually documented, open source, data processing package.

Pleiades reached its first data milestone today. We've loaded up all point features from the Barrington Atlas Map 65: Lycia-Pisidia. Map 65 (dead center of the locator map) was compiled by C. Foss and S. Mitchell, and edited by R. Talbert (see credits). The Pleiades portal provides KML and GeoRSS views of all features and folderish collections of features. The latter are used within the site in conjunction with several OpenLayers-based maps.

Lycia was an early Greek colony in Asia Minor and, later, a Roman province. Pisidia is mountainous country, and its peoples mounted a long insurgency against Greeks and Romans. Archaeologists are active in this region: at Sagalassos and Choma (site currently down) in particular. The Choma network link from Pleiades is well worth a visit. The dig itself is found 1.5 kilometers NE of the 1:500,000 scale Pleiades placemark. Google has recent high-resolution imagery for the region, and you can easily see the site and excavation. The next development milestones for Pleiades focus on creating the scholarly workflow that will improve the locations, historical names, and bibliographic references of these features. Dare we call it "Scholarship 2.0"?

All contemporary features can be viewed using the Imperial Roman period network link.

Initial startup funding for Pleiades is generously provided by the U.S. National Endowment for the Humanities with a two-year grant (2006-2008) through its Preservation and Access Research and Development program. Hosting for Pleiades during this period is provided by the Stoa Consortium and the Collaboratory for Research in Computing for Humanities at the University of Kentucky.

Trey Beck is organizing a first local Plone meetup:

Friday October 13 at 6:00 pm at the Alliance Building, 1536 Wynkoop St (next door to the Tattered Cover in LODO). We'll have internet access and a projector, I think. Spread the word!

I'm looking forward to hearing what people are up to, and to showing off Pleiades and PrimaGIS.

Last week I made new releases of PleiadesGeocoder and PleiadesOpenLayers, the software that's providing the geo capabilities of the Pleiades Beta portal. I haven't been doing the best job of explaining the software, and people -- particularly those familiar with byzantine open source GIS software -- may have misconceptions about the complexity of these Plone products. This stuff is dirt simple. PleiadesGeocoder (soon to be renamed to PleiadesGeo) allows you to annotate Plone content with georeferencing, and provides XML feed-like views of that content for consumption by geographic and mapping applications. The geo-annotations are inspired by EasyCommenting and PloneGoogleMaps (two interesting projects in their own rights), but the views are original.

What makes it all hang together? Reliable Zope 3 machinery and standards. The Pleiades products use Five, so configuring the geo-annotation of your custom content types is only a matter of adapting to IGeoItemSimple and registering your adapter with ZCML. KML and GeoRSS aren't my favorite languages in the world, but they certainly have momentum and plenty of application support. Combining GeoRSS with Atom works well for me, and will be fully supported in OpenLayers 2.2.

Pleiades uses JSON when transporting map contexts and map features from Plone to our OpenLayers-based javascript applications. Our evolving flavor of geo-JSON is documented in the Pleiades wiki. I'm curious to find out if anyone else is doing something similiar.

The PleiadesGeo software I've been developing serves up Atom feeds, and now it seems we can suck such feeds back in. I asked Stephan Richter at the Plone Conference whether Plone would benefit from standardizing on Atom. His take was that Atom is too generic, and that the applications developed by Lovely Systems needed richer and more precise expression. I'm still interested in seeing what we can accomplish using more generic structures.

I get to work on something closely related today. PleiadesGeo already serializes content to KML for display in Google Earth. Now we're working on opening up the inbound lanes.

I spent a bit of the holiday explaining the Pleiades project to my family, and how it compares to Wikipedia and Citizendium. Like Citizendium, we aim to expertly moderate openly contributed knowledge. On the other hand, we're not forking the entirety of Wikipedia, but instead are scoping down and building upon an unequaled scholarly work -- the Barrington Atlas. Ben Vershbow, in Scholarpedia: sharpening the wiki for expert results (via Peter Suber), says we're on the right track:

One problem of open source knowledge projects is that they're often too general in scope (Scholarpedia says it all). A federation of specialized encyclopedias, produced by focused communities of scholars both academic and independent -- and with some inter-disciplinary porousness -- would be a more valuable, if less radical, counterpart to Wikipedia, and more likely to succeed than the Citizendium chimera.

Expertise will continue to have value in our wiki future. I'm already convinced that Pleiades has a solid mission, but it's nice to find reinforcements.

Platial's Chris Goad is offering JDIL as a way forward for Geo-JSON. JDIL (I presume this is an acronym for JSON Data Integration Language) is used at Platial to map RSS 1.0 XML feeds to JSON [example feed]. It's thorough and seems a decent solution to the problems particular to RSS 1.0, but those problems don't exist in my applications.

The reason for the interest in Geo-JSON, for those who aren't familiar with JSON, is twofold: JSON can be evaluated by your browser's javascript engine, and, wrapped in javascript, can exploit a hole in your browser's same-domain policy (nicely explained by Douglas Crockford here) and allow you to integrate geo-data from diverse sites. The same-domain policy prevents us from using XML, and efforts to port XML features to JSON seem to be an inevitable result. I'm not as pessimistic about these efforts as some.

The Geo-JSON I am using for Pleiades [wiki, example] is inspired by Atom 1.0. There's no pastiche of namespaces, and, as far as I'm concerned, any specialized content could be carried as an escaped XML string property. I also prefer arrays of numeric coordinates to JDIL's georss:type string property, as it removes the need to parse a string on the client end. What to do about polygons with holes or multi- types is an open question. I think the way to go is to follow WKT, but with arrays of numbers instead of text.

I'm finding a fair amount of other placemarks in the neighborhood of some interesting ancient places from Pleiades. Check out the ancient settlement of Caunus [direct network link], and the host of interesting photos in the Panoramio layer. If you search for "roman" in this spatial context you get a number of Pleiades placemarks, but there are a few from other sources, notably the "theatre of Caunos", and the co-located Panoramio mark. There are also nice shots of remarkable rock tombs near Karpasyanda.

Selected places from map 65 of the Barrington Atlas, covering Lycia and Pisidia, are at http://pleiades.stoa.org/places/nwlink.

PleiadesGeocoder provides a portal geocoding tool and methods for producing KML and GeoRSS representations of Plone content. I've made a 0.6.2 release [plone.org, icon.stoa.org] on the way to the next Pleiades milestone site release.

What's Plone? The Python CMS, which, as Stefan Geens reminded me the other day, is still completely unknown to PHP fans.

I'm off on vacation for a few days after finishing the latest Pleiades site migration and release. Our master KML file is now at http://pleiades.stoa.org/places/nwlink. That's 304 places in ancient Lycia and Pisidia (southwest coast of modern Turkey) from map 65 of the Barrington Atlas. There are 102 map pages to go, and we'll eventually have about 50,000 ancient places (with extensive bibliography) online next spring. In case you have a Barrington Atlas handy, the map 65 grid is available at http://pleiades.stoa.org/places/BA065grid.kml.

It will take a while for Google's index to catch up with our changes, but thanks to mod rewrite and a little scripting, anything you find through a Google Earth search is properly redirected to our new URLs.