Temporal Gisplay

João Moura Pires (superv.), Fernando Pedro Reino da Silva Birra (co-superv.), Universidade NOVA de Lisboa, December 2017.
Keywords: Thematic Maps, WebGL, Analytical Visualization, Time
Abstract: Nowadays, due to the ubiquity of the devices that gather information, ranging from computers to mobile phones, an increasing amount of data is produced, and such data
contains the temporal and spatial component because those devices are mobile and have their own capability of collecting location information. Thematic maps are one important tool for the analysis of phenomena through time and space and they’re a problem remaining to be solved. It was clear that there wasn’t an API to build thematic maps based on the web, that enables interaction, dealing with millions of points, using the best principles of cartography and data visualization while allowing to deal with millions of points and still maintaining fluid interaction. All the evaluated APIs during this dissertation had one or more aspects that wouldn’t satisfy some of the above characteristics, with a particular mention to the API Gisplay because this API adopts the WebGL technology as a solution to obtain the required performance. Despite this, the Gisplay API does not support the temporal component and has huge limitations from the point of view of visual variables visualization. On this dissertation was proposed and implemented the API Temporal Gisplay, an JavaScript API, with a high level of abstraction and easily extensible with the uppermention characteristics. The evaluation that was done shows that the API Temporal Gisplay is
able to deal with millions of points, enables the use of multiple visual variables, is able to use the temporal component and has a set of thematic maps that can be used to visualize
different scenarios.

Presentation and MSc Thesis Document

Videos

Video 1:
Description: In this video you can see an example of a map by area (Choropleth) where you are viewing the employment rate for people between 15 and 24 years of age for each country. We have the possibility to visualize various moments of time, as well as to perform zoom, pan and picking operations (click on map elements).
File: Choropleth.mp4

Video 2:
Description: In this video you can see an example of a point map for taxi travel in New York. It is also possible to see the interactivity provided by the API, such as caption filtering and time-controlled for intervals.
File: DotMap NYC.mp4

Repository

The Temporal Gisplay code is available at this GIT repository.