Locus is a news archive visualisation that maps Guardian articles to places over time - a spatial & temporal mapping of events and media attention in the last decade. We’re using the Guardian Open Platform because it provides an API that can be queried by date, and an archive going back over 10 years.

Each place is represented as a geo located dot that changes scale in proportion to that places appearance in news articles over time. As the time slider selection changes the circles grow and shrink giving a picture of which locations are in the news at any given time. To see the all the news articles mapped, you can extend the time slider to the full search period. You can click on the places to see the news headlines for that place and time period. The headlines link through to the online articles at the Guardian.

There are two versions of the project: Locus Afganistan, and Locus Iraq.

If you would like to comment or feed back on this visualisation please do so on the blog.

Instructions //

• Click on a node to view the news articles for that place.
• Use the time slider at the bottom to change the date range, to play and to step forwards and backwards. To get an overview, drag the date handles to cover the full date range.

How it was Built //

The project was built using Yahoo! GeoPlanet API and Guardian Open Platform.

Our first step is to retreive a list of places belonging to a particular country. Yahoo! GeoPlanet provides a simple way to do this. The descendent query returns a hierarchy of places within an administrative region. If you request the long representation of these places, you also get the longitude and latitude, so their positions can be plotted.

For each place name a search is made against the Open Platform API, and the list of places is mapped to a list of articles. To minimise the number of false results, we include the country name in the search term. This approach works better for some place names than others, so we filter results for place names that correspond to common words and names of people.

Once the data has been processed, the visualisation plots each place as a circle, whose area is directly proportional to the number of results for the selected timeframe.