Thematic Cartography

Flow Maps

We develop algorithms for creating flow maps showing linear movements between two places with curved lines of varying width. The geometry of flows is bent to reduce the number of graphic conflicts among flows.

Funding by National Science Foundation NSF grant #1438417 with PI Bernhard Jenny, co-PI Helen Jenny, co-PI Eugene Zhang (Computer Science), research assistant Brooke Marston (all Oregon State University) and grant #1437292 with PI Ian Muehlenhaus, James Madison University.


Jenny, B., Stephen, D. M., Muehlenhaus, I., Marston, B. E., Sharma, R., Zhang, E. and Jenny, H. (2017).
Design principles for origin-destination flow maps.
Cartography and Geographic Information Science.
DOI: 10.1080/15230406.2016.1262280



2016 URISA GIS-Pro Student Competition for Daniel Stephen
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Design principles for origin-destination flow maps.


Dot Maps

We explore methods from computer graphics for improving the placement of dots in maps. Simple random placement leads to local clustering of dots that is misleading, as these patterns suggest a spatial pattern that may not exist. Random placement also creates overlapping dots, which are not countable. We adapt sampling methods from computer graphics to solve these problems.

Researcher: Nick Arnold

Jenny, B., Hutzler, E. and Hurni, L. (2010)
Point pattern synthesis.
The Cartographic Journal, 47-3, p. 257–261.
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Legends for Proportional Symbols

Maximum:
Minimum:
Size:
Font Size:
Distance:
Breaks:
Self-adjusting legends for proportional symbol maps only display intermediate symbols for round values (for example 100, 250, 500, 1000, 2500, etc.). The legend always displays a set of appropriate intermediate symbols, even when the minimum and the maximum values are very large or very small.

Jenny, B., Hutzler, E. and Hurni, L. (2009)
Self-adjusting legends for proportional symbol maps.
Cartographica, 44-4, p. 301–304.


More information and code…