Monday, March 25, 2013

Another interactive version of

John Snow's cholera map

After reading the article: 'John Snow's data journalism: the cholera map that changed the world' by Simon Rogers, who referenced to Robin Wilson at Southampton University, who georeferenced  the original map of John Snow from 1854 and generously published the GIS data for reuse, I had to do something with this data.

Here is the result. It needs a browser with HTML5 capabilities to show up.

Hint: you can open a menu on the left with the list symbol button and change the chart parameters. 

So, please try it and feel free to comment if you like it or not.


  1. This look's great - I love what you've done with my data. I think it improves on the Guardian's map significantly as it has a key, the actual numbers are given on the points, the info tool works nicely etc :-)

    I'm intrigued: what tool did you use to make the map? And did you code it all yourself, or did you use a tool which put it all together? Whatever it is, it looks great.


    1. Thank you very much for your comment, I am happy, you liked the map. To answer your question about the way its done: its a framework I called iXmaps, with a stand alone SVG map that holds the geographic points and its own JavaScript to produce the charts; its generated from a QGis project by a proprietary tool; underneath there is a tilemap wrapped by the Mapstraction library. To put it all together, synchronize the maps and export an api, there is another JavaScript lib with jQuery (+ui,+mobile); its all static files and there is a REST interface to control the client side map and chart creation. I hope I could answer your question. For any other, feel free to contact me.

  2. This looks great! How did you label the counts in the point symbol?