Three major goals of visualization:
- exploratory analysis
- confirmatory analysis
“dot distribution map”
Source: Wikimedia Commons [http://en.wikipedia.org/wiki/File:Snow-cholera-map-1.jpg]
Why build (geo-)visualizations in the browser?
it is the most installed language in the world: the one language
you can be confident is installed on the user's computer.
- Similarly, all modern browsers (with the introduction of IE9 in 2011)
can render Scalable Vector Graphics (SVG), including mobile
devices that are unable to render Flash.
us to create sophisticated charts that are accessible by a
majority of Internet users.
Source: Dewar, Mike. 2012. Getting Started with D3. O’Reilly Media, p. 1f.
A web-based (geo-)visualization...
- does not require any additional software (modern browsers are installed on almost all computers)
- can be easily published on the internet (with no additional plugins needed)
- can be easily enhanced with interactive features (e.g. mouse-over, mouse-click, etc.)
- uses open-source technology
- is scalable / can be zoomed in
- can be exported as PDF
- uses SVG (scalable vector graphics)
- is easily customizable
Data visualization is a process of mapping data to visuals
what kind of data do we need?
- geocoordinates of your locations
- a suitable framework to make geomapping easy
- polygons for displaying countries, continents of the area
Some useful tools
[press down arrow to see Google Earth example and Hessen Dialekterkenner]
D3 (Data-Driven Documents)
- D3 connects the data to web-based documents, meaning anything that can be rendered by a web browser, such as HTML and SVG.
- The project is entirely open source and freely available. You may use, modify and adapt the code for noncommercial or commercial use at no cost.
Source: Murray, Scott. 2013. Interactive Data Visualization. O'Reilly Media. p. 7.
D3 geovisualization examples
[press down arrow for cartogram example]
Source: Bak, Peter, Thomas Mayer, Christian Rohrdantz, David Spretke, Miriam Butt, Frans Plank, Daniel A. Keim. 2011. ￼Cartogram for the Areal Distribution of Languages.
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