Two items on maps for the blind and visually impaired—a subject I find terribly interesting:
Greg Miller of National Geographic’s All Over the Map reports on a new tactile atlas of Switzerland, which “is printed with special ink that expands when heated to create tiny bumps and ridges on the page.” I can’t find a direct link to said atlas, but Greg interviews Esri cartographer Anna Vetter, who led the project.
Almost all web mapping libraries render maps using Web Mercator, making an assumption that you generally can’t change out-of-the-box. This has advantages, but it posed a real challenge for us when we set out to build the Washington Post’s live election results map, where using the Albers USA projection was an important requirement. To meet that requirement, we built a pipeline to pre-process geometries.
It’s a bit of a kludge, a way of fooling Mapbox into showing a different projection—latitude/longitude coordinates aren’t accurate any more—but it’s an impressive stab at a real problem. The Dirty Reprojectors web app demonstrates the possibilities, with all the projections available through the d3-geo and d3-geo-projection libraries. [James Fee]
Virginia Official State Transportation Map (detail)
Official highway maps—paper highway maps—are still a thing: the Norfolk Virginian-Pilot has a profile of the Virginia Department of Transportation’s sole cartographer, Dwayne Altice, who’s responsible for the biennial updates to that state’s official transportation map. Includes some interesting behind-the-scenes detail about how the map is made—and how it used to be made (layers and layers of film). [WMS]
Caitlin at Geo Lounge on pantographs: “Before the use of computers to replicate and manipulate maps, a pantograph was one of the ways used to either reduce or enlarge the size of a map while reproducing an accurate copy of the original map.” I did not know about pantographs—they seem to have been widely used in drawing and diagramming. Maps too, it would seem.
Mapping U.S. election results by county and state is a bit different than mapping results by electoral or congressional district, because counties and states don’t have (roughly) equal populations. Choropleth maps are often used to show the margin of victory, but to show the raw vote total, some election cartographers are going 3D.
The CIA also has a Flickr account, where they’ve posted a number of their maps in various albums sorted by decade (all of which are labelled “Cartography Maps,” which sounds dumb until you realize they probably mean Cartography Center Maps). I think the Cartography Tools album is even more interesting than the maps.
The white underlying geographic map places states in their familiar size, shape and location, allowing them to be identified quickly. Using a cluster of dots rather than a solid fill to represent the outcome ensures that the amount of red and blue on the map accurately reflects states’ weight in the election outcome, rather than the (irrelevant) surface area.
Like the tiled grid cartogram, the number of electoral votes in each state is easy to compare visually without counting or interpreting numbers printed on the map. Because each electoral vote is a discrete mark, it is possible to accurately represent the split electoral votes that are possible in Maine and Nebraska, or the possibility of a faithless elector.
Japan’s Good Design Awards have been announced for 2016, and the Grand Award has gone to an unusual map. The AuthaGraph World Map “is made by equally dividing a spherical surface into 96 triangles, transferring it to a tetrahedron while maintaining areas proportions and unfolding it to be a rectangle.” Follow that? Sphere to tetrahedron to rectangle.
The brainchild of designer Hajime Narukawa, the AuthaGraph map was first released in 2010. What’s it for? In many ways it’s sort of a Japanese Peters projection: it aims to maintain the relative sizes of the continents. From the page selling the map outside Japan:
Every world map that has been invented since the Mercator Projection was first revealed in 1569 can be divided into two groups. One group fits the world into a rectangle by distorting the continents. The other group corrects the distortion, but at the cost of the rectangular shape. This is what drove Narukawa to create a map which is rectangular like the Mercator Projection map, and yet correctly projects the continents like the Dyxmaxion Map (revealed in 1946).
Today, print subscribers to the New York Times were treated to a fold-out map showing a choropleth map of the 2012 election results at the ZIP code level (above). “The map is part of a special election section that aims to help explain the political geography of the United States — identifying where people who are conservative and liberal live and pointing out how physical boundaries, like the Rio Grande and the Cascade Mountains, often align with political ones,” writes the Times’s Alicia Parlapiano.
Parlapiano’s piece is in fact a lengthy tutorial on how to read election maps, along the lines of the pages I linked to in last week’s post on election map cartography—it outlines the problems of state-level election maps and choropleth maps that privilege area over population, for example, and shows some other ways of depicting the results.
I can only conclude that both the Times and the Post are making efforts to educate their readers before the election results start coming in, one week from tonight. (Deep breath.)
With less than two weeks before the 2016 U.S. presidential election, it’s time for a refresher on election map cartography, particularly in the context of U.S. presidential elections.
Cartograms
2012 U.S. presidential results. At right, a cartogram scaled by electoral vote. Maps by Mark Newman.
Let’s start with the basics: at All Over the Map, Greg Miller explains the problem with U.S. presidential election maps—big states with few electoral votes look more important than smaller states with more votes—and introduces the idea of the cartogram: a map distorted to account for some variable other than land area.
The map may not look advanced today, but in 1883 it broke new ground by enabling Americans to visualize the spatial dynamics of political power. Readers responded enthusiastically. One reviewer pointed to the Republican counties in Arkansas—something left invisible on a map of the Electoral College returns—and wondered what other oddities of geography and history might be uncovered when election returns were more systematically measured. In other words, the map revealed spatial patterns and relationships that might otherwise remain hidden, or only known anecdotally. Perhaps its no coincidence that at the same time the two parties began to launch more coordinated, disciplined, nationwide campaigns, creating a system of two-party rule that we have lived with ever since.
(This map also inverts the modern colours for the two main U.S. political parties: here the Democrats are red and the Republicans are blue. Those colours were standardized only fairly recently.) [Geolounge]
For other ways of mapping election results, see this gallery of thematic maps, which includes things like 3D choropleth maps, dot density maps, and all kinds of variations on cartograms and choropleth maps. There’s more than one way to map an election. [Andy Woodruff]
Alan Smith of the Financial Times adds to the conversation about when to use a map to present your data, when not to—he gives an example where a gridded infographic is a much better choice than a map—and when more than one map is required to tell the whole story. “So as lovers of maps, we are keen to create beautiful ones whenever they offer a crucial addition. Truly appreciating them, however, means not defaulting to a map just because you can. Like a lot of things in the world of data visualisation, the right way to use them is to follow the mantra ‘fewer, but better’.” [WMS]
Map Men is a YouTube series by comedians Jay Foreman and Mark Cooper-Jones. It’s funny as hell, and quite informative too: it’s two silly people being very smart about often-silly cartographical situations. Six episodes so far; I hope they make more. [Geographical]
