July 14, 2016
They say, "a picture is worth a thousand words." As a scientist, I need to scan many journal articles for relevance, and the best way to do this is by looking at the included graphs and other images. This is useful, especially, in papers not written in English, so my limited foreign language skills are not overly taxed. That's why it's important for scientists to clearly render their images.
In our computer age, Information graphics (infographs) and scientific visualization have become research areas in themselves, but they have a long history. When discussing graphical representation of data, it's traditional to mention Charles Joseph Minard's famous cartograph, a 62 x 30 centimeter lithographic depiction of Napoleon's 1812 Russian campaign that shows troop numbers, their movement, and temperature (see figure).
While in elementary school, my daughter had an assignment to produce charts and graphs of data. Having a scientist father was a burden most of the time, but it helped her in creating a novel bar chart of the numbers of bathroom fixtures in the United States. Instead of bars, she produced arrays of sinks, toilets, and bathtubs to lengths that matched their numbers. She was able to do this using a primitive "photoshop" style program that worked in the Windows operating system of that time. This technique, as applied to a chart of membership in the major science and engineering professional associations, is shown below.
Popular among bloggers is the word cloud, a representation of the frequency of keyword use in which the words themselves are sized according to their importance (see figure). While there are several online word cloud generators, the free and open-source statistics programming language, R, has a toolset that allows detailed development of word cloud representations.
One of the more interesting data representations is the cartogram, which is typically a map in which the map elements have been distorted so that their areas scale with a variable, such as population, income, carbon emission, etc. A simple cartogram of population is shown in the figure. A review article on cartograms has been posted to arXiv by doctoral candidate, Sabrina Nusrat, and professor Stephen Kobourov of the University of Arizona Department of Computer Science.
As can be imagined, area cartograms can be created in a panoply of pleasing forms that either attempt to reproduce the spatial arrangement of the original map by distorting its elements to scale with the variable of interest; or, to just place shapes of appropriate area on the plane. As can be seen in the following example of Nusrat and Kobourov, circles of appropriate area have been placed in the relative location of the US states on the plane to indicate the concentration of Starbucks and McDonald's locations.
Nusrat and Kobourov list quite a few cartogram techniques and historical examples in their paper.[1-2] The example of the above figure is a Dorling type cartogram, and it inspired me to attempt a similar cartogram program. My C language program (source code in my typical amateur coding style can be found here), accepts as an input a CSV format file of states and some data attribute of the states, and it outputs an SVG image as shown below.
Unlike a true Dorling cartogram, this program overlaps circles, thereby preserving the map shape. While this might be a valid reason, the actual reason is that this was easier to code. Some example data files are the number of representatives in the house of representatives, and population. A skilled programmer should be able modify the program to give a true Dorling representation, or experiment with other shapes.
|Concentration of Starbucks and McDonald's locations in the United States. The circle size is indicative of the number of Starbucks coffee shops, while the intensity of the shading indicates the number of MacDonald's restaurants. The correlation is easily seen through this representation. (Figure 16 from ref. 2, used with permission.)[1-2]|
- Sabrina Nusrat and Stephen Kobourov, "The State of the Art in Cartograms," EuroVis 2016 - the 18th EG/VGTC Conference on Visualization, Groningen, the Netherlands (June 6-10, 2016). To appear, Computer Graphics Forum, vol. 35, no. 3 (2016).
- Sabrina Nusrat and Stephen Kobourov, "The State of the Art in Cartograms," arXiv, May 30, 2016.
- Some interesting maps, including a few cartograms, can be seen at the David Rumsey Map Collection, Cartography Associates.
Permanent Link to this article
Linked Keywords: A picture is worth a thousand words; scientist; scientific journal; journal article; Cartesian coordinate system; graph; image; academic publishing; paper; English language; foreign language; information Age; computer age; information graphic; scientific visualization; research; history; tradition; traditional; Charles Joseph Minard; cartography; cartograph; centimeter; lithography; lithographic; Napoleon; Russia; military campaign; troop; temperature; Réaumur scale; freezing; freezing point; water; boiling point; Wikimedia Commons; elementary school; daughter; chart; data; burden; bar chart; bathroom; United States; sink; toilet; bathtub; photoshop; computer programming; program; Windows operating system; science; engineering; professional association; American Physical Society (APS); Federation of American Societies for Experimental Biology (FASEB); American Chemical Society (ACM); Institute of Electrical and Electronics Engineers (IEEE); Inkscape; blog; blogger; tag cloud; word cloud; statistical frequency; keyword; free and open-source software; statistics; programming language; R-programming language; Web 2.0; buzzword; cartogram; map; area; variable; population; income; greenhouse gas; carbon emission; review article; arXiv; doctoral candidate; Sabrina Nusra; professor; Stephen Kobourov; University of Arizona Department of Computer Science; United States Census; New Jersey; panoply; plane; circle; US state; concentration; Starbucks; McDonald's; United States; fast food restaurant; correlation; history; historical; Danny Dorling; C language program; source code; amateur; cartogram.c; CSV format file; SVG image; United States House of Representatives; radius.
Latest Books by Dev Gualtieri
Thanks to Cory Doctorow of BoingBoing for his favorable review of Secret Codes!
Blog Article Directory on a Single Page
- Levitation - March 27, 2017
- Soybean Graphene - March 23, 2017
- Income Inequality and Geometrical Frustration - March 20, 2017
- Wireless Power - March 16, 2017
- Trilobite Sex - March 13, 2017
- Freezing, Outside-In - March 9, 2017
- Ammonia Synthesis - March 6, 2017
- High Altitude Radiation - March 2, 2017
- C.N. Yang - February 27, 2017
- VOC Detection with Nanocrystals - February 23, 2017
- Molecular Fountains - February 20, 2017
- Jet Lag - February 16, 2017
- Highly Flexible Conductors - February 13, 2017
- Graphene Friction - February 9, 2017
- Dynamic Range - February 6, 2017
- Robert Boyle's To-Do List for Science - February 2, 2017
- Nanowire Ink - January 30, 2017
- Random Triangles - January 26, 2017
- Torricelli's law - January 23, 2017
- Magnetic Memory - January 19, 2017
- Graphene Putty - January 16, 2017
- Seahorse Genome - January 12, 2017
- Infinite c - January 9, 2017
- 150 Years of Transatlantic Telegraphy - January 5, 2017
- Cold Work on the Nanoscale - January 2, 2017
- Holidays 2016 - December 22, 2016
- Ballistics - December 19, 2016
- Salted Frogs - December 15, 2016
- Negative Thermal Expansion - December 12, 2016
- Verbal Cues and Stereotypes - December 8, 2016
- Capacitance Sensing - December 5, 2016
- Gallium Nitride Tribology - December 1, 2016
- Lunar Origin - November 27, 2016
- Pumpkin Propagation - November 24, 2016
- Math Anxiety - November 21, 2016
- Borophene - November 17, 2016
- Forced Innovation - November 14, 2016
- Combating Glare - November 10, 2016
- Solar Tilt and Planet Nine - November 7, 2016
- The Proton Size Problem - November 3, 2016
- Coffee Acoustics and Espresso Foam - October 31, 2016
- SnIP - An Inorganic Double Helix - October 27, 2016
- Seymour Papert (1928-2016) - October 24, 2016
- Mapping the Milky Way - October 20, 2016
- Electromagnetic Shielding - October 17, 2016
- The Lunacy of the Cows - October 13, 2016
- Random Coprimes and Pi - October 10, 2016
- James Cronin (1931-2016) - October 6, 2016
- The Ubiquitous Helix - October 3, 2016
- The Five-Second Rule - September 29, 2016
- Resistor Networks - September 26, 2016
- Brown Dwarfs - September 22, 2016
- Intrusion Rheology - September 19, 2016
- Falsifiability - September 15, 2016
- Fifth Force - September 12, 2016
- Renal Crystal Growth - September 8, 2016
- The Normality of Pi - September 5, 2016
- Metering Electrical Power - September 1, 2016
Deep Archive 2006-2008