A map which shows statistical information in diagrammatic form Statistics first , geographical accuracy second
Traditional shaded map including info on statistics and Cartogram with regional areas distorted to represent the statistic
Similar for GCSE performance in England
Create, Share and reuse Production strength service and toolset Break the barriers to current creation by non specialists
Using work done on Unlock Text API For scaling - Use of multiple instances on multiple servers in the cloud ScapeToad is a cross-platform, open-source application for producing cartograms. Its written in Java and uses the ESRI Shapefile format for input and output.
API is the main guts of it – interfaces with the guts of Scape Toad Allows upload and download of input and output files Website uses a wizard to guide user through creation process
Access to gallery to view and download existing Cartograms fir unregistered users Registered users able to create new cartograms and contribute them to gallery
Osgis sept2012 cartogrammar
OSGIS 2012, Nottingham Sandy Buchanan Project ManagerSlide 1 of ## <<Enter presentation title here>>
What is a Cartogram?car·to·gram/ˈ kärtəˌ gram/ A map on which statistical information is shown in diagrammatic form. A small diagram on the face of a map, showing quantitative information. An abstracted and simplified map the base of which is not true to scale.
Project Goals • To enable social scientists and others to create, share and reuse bespoke cartograms • The project will offer a production strength generic service and associated toolset. • It will alleviate the problems associated with production complexity and computational expense.Slide 6 of ## <<Enter presentation title here>>
Technology Being Used • Celery and RabbitMQ to manage the distributed task queue including the ability for multiple instances on multiple servers i.e. send it to the cloud if required • Using ScapeToad Cartogram generation. ScapeToad is a cross-platform, open-source application for producing cartograms. Its written in Java and uses the ESRI Shapefile format for input and output. • The algorithm used to compute the cartogram is based on the diﬀusion-based method for producing density equalizing maps by Michael T. Gastner and M. E. J. Newman
Outputs • The main output from the project is an API • The API is then used to service a website allowing non technical users to generate cartograms. • There is also a ‘widget’ allowing users to embed the basic website functionality in their own site. • The API, can of course, be used directly
The API • The API is accessed through the use of cURL commands or a REST Console/Client. These are available as add-ons for Chrome and Firefox web browsers. • Documentation and user guide available soon
The API• The API • Allow authenticated users to upload a validated, virus checked shapefile. • The shapefile can be ‘simplified’ to reduce computational time. • Select polygon layer to transform and the metric variable linked to that layer that will become the metric layer for the cartogram • Utilise the Gastner/Newman diffusion-based algorithm • Allow the computation to be farmed out to multiple servers if required for complex cartograms • Allow retrieval of new cartogram, shapefiles, distortion grid and metadata
The Website • Searchable gallery of user contributed cartograms • Cartogram generation interface • Multiple cartograms from a single shapefile • Output generation • Download • Access to ‘Widget’ Code • Access to API documentation • Further Cartogram resources