A Manual Approach to Cartogram Construction using Triangular Lattice TransformationBarry Kronenfeld, Eastern Illinois UniversityAutomated algorithms are limited in their ability to produce aesthetically pleasing cartograms, while currently available methods for manual cartogram construction (i.e. block cartograms) do not define a continuous spatial transformation. I propose an alternative framework for cartogram construction using triangular lattice transformation. In the proposed framework, a regular lattice is transformed by repositioning vertices until vertex density approximates population density, forming a dot-density map. The original and transformed lattices define a continuous transformation from geographic space to cartogram space. The transformation is reusable and can be applied to any geographic dataset, acting as a type of map projection. Sample tools for constructing and applying cartograms are demonstrated, and the approach is illustrated with a population cartogram of Illinois, USA. By separating the task of defining a cartogram from the map design process, the proposed framework aims to facilitate more widespread application of cartograms to the analysis of population-dependent variables.
View presentation »Exploring interoperability: Using Python to Reverse Engineer Exported GraphicsMike Foster, MITCartographers, Designers, and Planners spend countless hours in graphic design software illustrating maps, charts, and graphics to create rich stories. The software, including Adobe Ilustrator, Adobe Photoshop, Inkscape, and GIMP, allows for rich illustration and complex graphic work that are beyond the scope and goal of traditional analytical GIS, but design tasks often require access to the same datasets. Most GIS support exporting of features to graphics format, but without the help of expensive licenses or tedious referencing, the process can be decidely one directional and there is no direct route to bring the datasets back into GIS. This session details the coding and creation of a Python-based tool that reverse engineers the export process, establishing a workflow that serves to read an Adobe Illustrator file, extract geographic features, and create referenced shapefiles that can be propagated forward in GIS.
View presentation »Dimensions of Uncertainty Visualization ResearchJennifer Mason, Penn State UniversityDavid Retchless, Penn State UniversityAlexander Klippel, Penn State UniversityIn recent years, uncertainty visualization techniques have taken a larger role in research as users have begun to adopt geospatial uncertainty visualization as an efficient mode of communication. This research surveys the literature on geospatial uncertainty visualization and classifies research in this subfield into different dimensions. These dimensions were borne through a systematic review of uncertainty visualization literature, iteratively identifying major topics and grouping them into similar categories, resulting in a classification of the field. Finally, a graphic was designed reflecting this classification to both organize and conceptualize the entire research field in a new way and to efficiently assist readers in quickly grasping the topics within an uncertainty visualization research paper at a glance. This research will help people develop a more thorough understanding of uncertainty visualization research while finding gaps that researchers should attend to in the future.
View presentation »Thematic mapping with free software PhilCartoKazimierz Zaniewski,
University of Wisconsin-OshkoshIn addition to ArcGIS and other major mapping software packages, there are several less known but fairly powerful programs designed for generating high quality thematic maps. One of them is PhilCarto, a free software developed and maintained by a French geographer at the University of Bordeaux. This mapping software is capable of producing all major types of thematic maps, including choropleth, proportional symbol, bar graph, pie chart, dot density, flow, 3-D surface, and gravity maps. It also has a set of statistical tools for mapping the results of exploratory data analysis, including ternary diagrams and regression, factor, and cluster analyses. The PhilCarto cartographic output is of very high quality and can be exported to illustration software for final touches. A companion to PhilCarto is PhilDigit, a boundary creation (digitization) and manipulation software. It can import and export ArcGIS (shapefiles) and MapInfo (mif/mid) boundary files.
View presentation »Space and time with cubes and coxcombsKenneth Field, ESRIMapping multivariate data over time is a challenge for cartography. In this presentation I review two techniques that perhaps haven't seen as much love as they deserve and show how we might dust them off for a new generation of map-makers.
Florence Nightingale worked to improve sanitary conditions in military hospitals. Her reports included rose diagrams (colloquially referred to as a coxcomb). Here, we explore the structure of the coxcomb and introduce a tool to create data-driven, spatially located coxcombs using ArcGIS. Swedish geographer Torsten Hägerstrand proposed the space-time cube (STC) as a framework for studying interaction and movement of individuals in space and time in 1970. Here, we show how to construct a STC in ArcGIS and publish directly to a 3D interactive web scene in a way that overcomes many of the difficulties..
Now that technology is catching up with these techniques it's time that we, as cartographers, put them to work.
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