OpenStreetMap for disaster response – raw notes from Harry Wood talk

Very raw, sometimes verbatim but doubtless flawed notes from Harry Wood‘s excellent talk at Open Data Institute in London. #odifridays Many thanks to Harry for a great talk and to ODI for putting together these lunchtime lectures. The ODI have also published slides and audio from the talk. “An introduction to OpenStreetMap, the UK born […]

Remembering Aaron Swartz

“One of the things the Web teaches us is that everything is connected (hyperlinks) and we all should work together (standards). Too often school teaches us that everything is separate (many different ‘subjects’) and that we should all work alone.” —Aaron Swartz, April 2001. So Aaron is gone. We were friends a decade ago, and […]

Learning WebGL on your iPhone: Radial Blur in GLSL

A misleading title perhaps, since WebGL isn’t generally available to iOS platform developers. Hacks aside, if you’re learning WebGL and have an iPhone it is still a very educational environment. WebGL essentially wraps OpenGL ES in a modern Web browser environment. You can feed data in and out as textures associated with browser canvas areas, […]

Schema.org and One Hundred Years of Search

A talk from London SemWeb meetup hosted by the BBC Academy in London, Mar 30 2012…. Slides and video are already in the Web, but I wanted to post this as an excuse to plug the new Web History Community Group that Max and I have just started at W3C. The talk was part of […]

Inmaps

From LinkedIn’s networking graphing service; see also my map I’ve been digging around in graph-mining and visualization tools lately, and this use at LinkedIn is one of the few cases where such things actually break through into mainstream usefulness. Well, perhaps not useful, but it’s nice to see how groups overlap. In my chart here, […]

Talis

Most of us around RDF and the Semantic Web have by now probably heard the news about Talis; if not, see Leigh Dodds’ blog post. Talis are shutting down their general activities around Semantic Web and Linked Data, including the Kasabi data marketplace. Failures are usually complex and Twitter is already abuzz with punditry, speculation […]

Everything Still Looks Like A Graph (but graphs look like maps)

Last October I posted a writeup of some experiments that illustrate item-to-item similarities from Apache Mahout using Gephi for visualization. This was under a heading that quotes Ben Fry, “Everything looks like a graph” (but almost nothing should ever be drawn as one). There was also some followup discussion on the Gephi project blog. I’ve […]

Building R’s RGL library for OSX Snow Leopard

RGL is needed for nice interactive 3d plots in R, but a pain to find out how to build on a modern OSX machine. “The rgl package is a visualization device system for R, using OpenGL as the rendering backend. An rgl device at its core is a real-time 3D engine written in C++. It provides […]

Dilbert schematics

How can we package, manage, mix and merge graph datasets that come from different contexts, without getting our data into a terrible mess? During the last W3C RDF Working Group meeting, we were discussing approaches to packaging up ‘graphs’ of data into useful chunks that can be organized and combined. A related question, one always […]

Linked Literature, Linked TV – Everything Looks like a Graph

Ben Fry in ‘Visualizing Data‘: Graphs can be a powerful way to represent relationships between data, but they are also a very abstract concept, which means that they run the danger of meaning something only to the creator of the graph. Often, simply showing the structure of the data says very little about what it actually […]

K-means test in Octave

Matlab comes with K-means clustering ‘out of the box’. The GNU Octave work-a-like system doesn’t, and there seem to be quite a few implementations floating around. I picked the first from Google, pretty carelessly, saving as myKmeans.m. These are notes from trying to reproduce this Matlab demo with Octave. Not rocket science but worth writing […]

Querying Linked GeoData with R SPARQL client

Assuming you already have the R statistics toolkit installed, this should be easy. Install Willem van Hage‘s R SPARQL client. I followed the instructions and it worked, although I had to also install the XML library, which was compiled and installed when I typed install.packages(“XML“, repos = “http://www.omegahat.org/R“) ‘ within the R interpreter. Yesterday I set […]

Exploring Linked Data with Gremlin

Gremlin is a free Java/Groovy system for traversing graphs, including but not limited to RDF. This post is based on example code from Marko Rodriguez (@twarko) and the Gremlin wiki and mailing list. The test run below goes pretty slowly when run with 4 or 5 loops, since it uses the Web as its database, via […]

Video Linking: Archives and Encyclopedias

This is a quick visual teaser for some archive.org-related work I’m doing with NoTube colleagues, and a collaboration with Kingsley Idehen on navigating it. In NoTube we are trying to match people and TV content by using rich linked data representations of both. I love Archive.org and with their help have crawled an experimental subset […]