Posts Tagged ‘cartogram’

What if the largest countries had the biggest populations?

Monday, November 22nd, 2010

Created by Reddit user JPalmz, this cartogram-like graphic uses the country shapes from a normal world map but relabels them according to population ranking. Click on image for larger version.


Value-by-Alpha Maps, Cartograms, and More (Cartogrammer)

Thursday, June 17th, 2010


[Editor's note: Best practices on accounting for area-distortions normally present in conformal map projections by using cartograms and value-by-alpha alternatives. Check out the paper. Thanks ChartPorn!]

Republished from Cartogrammer.

The latest issue of the The Cartographic Journal (of the British Cartographic Society) contains a paper written by Robert Roth, me, and Zachary Johnson entitled “Value-by-alpha Maps: An Alternative Technique to the Cartogram.” The value-by-alpha map is something I have touched on here several times over the past year and a half (as has Zach on his blog), and about which I spoke at last year’s NACIS conference in Sacramento. With the publication of this paper, it’s high time I explained what it’s all about.

Value-by-alpha maps (hereafter shortened to VBA), like everything noble and good, have their roots in somebody complaining about something on the internet—me, about election cartograms. Seeking an alternative to what I think are ugly and unreadable election results cartograms, I worked with my Axis Maps dudes to create a 2008 U.S. election map that used transparency rather than size to vary the visual impact of map units, thinking that avoiding the distortion of these units into unrecognizable sizes and shapes would make the map easier to read.

Rob Roth, a stellar Ph.D. candidate and shameless county collector at Penn State (studying under The Beard himself, the illustrious Alan MacEachren) became interested in further developing the idea academically and enlisted my Axis Maps partner and radical raw milk zealot Zach Johnson (who wrote his master’s thesis on cartograms) and I to collaborate on the now-published Cartographic Journal article. We were all graduate students at Madison together once upon a time, and we make a good team—striking a perfect balance between study, practice, and chili-eating.

Enough backstory. I’ll summarize at moderate length the idea and what we wrote.

Continue reading at Cartogrammer . . .

UK election map and swingometer (Guardian)

Friday, April 30th, 2010


[Editor's note: Cartograms (1, 2) are all the storm in the UK in the lead up to the general election later this month. I first noted them via the Financial Times's print edition graphic and then came across this interactive version done by the Guardian (screenshot above). It combines the geography view typical in the US with a cartogram of the same. The cartogram does better at showing overall trends since each enumeration unit (election district) is the same size, where on the geography view some districts are super large and some (around London) are tiny as they are sized by area rather than population / electors. The Guardian's online version has search function as well as mouse over and the geography view zooms in to reveal those tiny districts. What's super amazing is the swingometer. It allows the user to see what would happen if the electorate "swings" towards one party or another both in numbers and on the maps. This would be fabulous to see in the US for our midterms. Quibbles with their map: I can't click and drag in the geography view to move the map, nor can I click and drag the detail box in the UK context map in the geography view. Overall A+ effort. And yet another reason why Steve Jobs, bless his heart, is crazy for thinking HTML5 should be the only game in town. These types of maps excel in Flash's compiled plugin runtime.]

Republished from the Guardian. Monday 5 April 2010.
By Mark McCormick, Jenny Ridley, Alastair Dant, Martin Shuttleworth

Browse the 2010 constituencies and use the three-way swingometer to see how different scenarios affect the outcome. This map is based on 2005 figures, notional or actual, and does not take account of byelection results. Full explanation here

Interact with the original at the Guardian . . .

News Dots (Slate)

Wednesday, September 9th, 2009


[Editor's note: This is one of the first tools I've seen that links topics, people & places into a network of graduated circles based on their ranking in the news. The circles are arranged based on their edge connections within the overall topology using the Flare visualization package in Flash AS3. As seen in the above screenshot, Germany is linked to Afghanistan, NATO, the Taliban, The Washington Post, and 20 other nodes. This project is one step forward in the vision I outlined in Topology and Projections: 21st Century Cartography. Disclosure: Slate is owned by the Washington Post Company, my employer, but I was not involved in this project.]

Republished from Slate.

Introducing News DotsAn interactive map of how every story in the news is related, updated daily.

Like Kevin Bacon’s co-stars, topics in the news are all connected by degrees of separation. To examine how every story fits together, News Dots visualizes the most recent topics in the news as a giant social network. Subjects—represented by the circles below—are connected to one another if they appear together in at least two stories, and the size of the dot is proportional to the total number of times the subject is mentioned.

Like a human social network, the news tends to cluster around popular topics. One clump of dots might relate to a flavor-of-the-week tabloid story (the Jaycee Dugard kidnapping) while another might center on Afghanistan, Iraq, and the military. Most stories are more closely related that you think. The Dugard kidnapping, for example, connects to California Gov. Arnold Schwarzenegger, who connects to the White House, which connects to Afghanistan.

To use this interactive tool, just click on a circle to see which stories mention that topic and which other topics it connects to in the network. You can use the magnifying glass icons to zoom in and out. You can also drag the dots around if they overlap. A more detailed description of how News Dots works is available below the graphic.

Interact with the original and learn more at Slate . . .

Flickr Geotagged Photos as Cartogram Map

Wednesday, April 22nd, 2009


[Editor's note: As more cameras and users tag their photos on upload into the Flickr pool, we can visualize where users are contributing via the above cartogram and below as 3d globe map. The cartogram source isn't attributed, but I like how it breaks out high and medium contribution areas in blue and pink, and then shows largly unpopulated areas (but still popular to photograph in the Amazon's case) in green, and then ocean areas in grey. Or thats my take on it ;) Thanks Lynda!]

Republished from Flickr user Straup and RevDanCatt.

Play movie at original site, screenshot below.

So, here it is, 24 hours worth of geotagged photos (64,410) from last Monday, March 23rd. Our numbers say that around 30% are normally private, giving us a total of around 92,000 geotagged photos for that day, which is just over 1 photo geotagged per second.

All the data was pulled down (using Processing, of all things) via the API, and probably took around 12 minutes (when it’s behaving itself) as I was being a) gentle with the servers b) was getting it as JSON which takes a while for Processing to parse each page (more information here:…. And then written to a flat file.

Continue reading and view video at Flickr . . .

Jump Starting the Global Economy (Wash Post)

Tuesday, April 7th, 2009


[Editor's note: Find the trends, group them together, and use that hierarchy (topology) as an access metaphor. And remember geography doesn't always need to mean map.]

Republished from The Washington Post.
Original publication date: March 29th, 2009.
By Karen Yourish And Todd Lindeman — The Washington Post.

The total amount of the stimulus packages approved by the G-20 countries amounts to $1.6 trillion. More than half of that comes from the United States.

Other maps and graphics that use grouping:

Greek To Me: Mapping Mutual Incomprehension (StrangeMaps)

Wednesday, March 11th, 2009

[Editor's note: This cartogram shows which languages cultures point to when they "just don't get it". Thanks Michael!]

Republished from StrangeMaps.
Originally published February 26, 2009.


“When an English speaker doesn’t understand a word of what someone says, he or she states that it’s ‘Greek to me’. When a Hebrew speaker encounters this difficulty, it ’sounds like Chinese’. I’ve been told the Korean equivalent is ’sounds like Hebrew’,” says Yuval Pinter (here on the excellent Languagelog).

Which begs the question: “Has there been a study of this phrase phenomenon, relating different languages on some kind of Directed Graph?” Well apparently there has, even if only perfunctorily, and the result is this cartogram.

Continue reading at StrangeMaps . . .

Per Capita Cartograms from ShowUSA

Thursday, March 5th, 2009

[Editor's note: I promoted ShowUSA's animated cartograms last week. This week I show off some of their new per capita cartograms and compare them to the raw number versions. Thanks Rick!]

CO2 emissions – per capita version
Click the interactive on the circular arrow to resize.

CO2 emissions – raw numbers version
Click the interactive on the circular arrow to resize.

Compare CO2 Emissions with Coal Fired Electric Power – raw numbers version
Click the interactive on the circular arrow to resize.

Stimulus Bill – per capita version
Click the interactive on the circular arrow to resize.

Stimulus Bill – raw numbers version
Click the interactive on the circular arrow to resize.

Tag Cloud: How Words Could End a War (NY Time)

Tuesday, March 3rd, 2009

[Editor's note: This op-editorial art piece (above) from the New York Times shows how a simple tag cloud can show an idea topology in a simple, powerful format. Full op-ed below.]

Republished from the New York Times.
Orig published: January 24, 2009

AS diplomats stitch together a cease-fire between Hamas and Israel, the most depressing feature of the conflict is the sense that future fighting is inevitable. Rational calculation suggests that neither side can win these wars. The thousands of lives and billions of dollars sacrificed in fighting demonstrate the advantages of peace and coexistence; yet still both sides opt to fight.

This small territory is the world’s great symbolic knot. “Palestine is the mother of all problems” is a common refrain among people we have interviewed across the Muslim world: from Middle Eastern leaders to fighters in the remote island jungles of Indonesia; from Islamist senators in Pakistan to volunteers for martyrdom on the move from Morocco to Iraq.

Some analysts see this as a testament to the essentially religious nature of the conflict. But research we recently undertook suggests a way to go beyond that. For there is a moral logic to seemingly intractable religious and cultural disputes. These conflicts cannot be reduced to secular calculations of interest but must be dealt with on their own terms, a logic very different from the marketplace or realpolitik.

Across the world, people believe that devotion to sacred or core values that incorporate moral beliefs — like the welfare of family and country, or commitment to religion and honor — are, or ought to be, absolute and inviolable. Our studies, carried out with the support of the National Science Foundation and the Defense Department, suggest that people will reject material compensation for dropping their commitment to sacred values and will defend those values regardless of the costs.

In our research, we surveyed nearly 4,000 Palestinians and Israelis from 2004 to 2008, questioning citizens across the political spectrum including refugees, supporters of Hamas and Israeli settlers in the West Bank. We asked them to react to hypothetical but realistic compromises in which their side would be required to give away something it valued in return for a lasting peace.

All those surveyed responded to the same set of deals. First they would be given a straight-up offer in which each side would make difficult concessions in exchange for peace; next they were given a scenario in which their side was granted an additional material incentive; and last came a proposal in which the other side agreed to a symbolic sacrifice of one of its sacred values.

Continue reading at New York Times . . .

Noncontiguous Area Cartograms (IndieMaps)

Monday, March 2nd, 2009

[Editor's note: Zach Johnson promotes his Actionscript 3 class for producing non-continuous cartograms and gives background on why these are better (and easier to construct) than Gaster-Newman continuous cartograms.]

Excerpted from IndieMaps blog by Zach Johnson.
View full blog post from Dec. 4, 2008.

Fully contiguous cartograms have stretched and distorted borders but perfectly maintained topologies. Like the Gastner-Newman diffusion-based cartograms we see all over the place. Though all sorts of cartogram designs have been produced, those with perfect topology preservation (fully contiguous cartograms) receive the majority of academic and popular press attention.

< snip >

Judy Olson (Wisconsin Geography alum natch) wrote the only academic article to focus specifically on this cartogram symbology in 1976. She believed noncontiguous cartograms held three potential advantages over contiguous cartograms (I’ve three more below):

  1. “the empty areas, or gaps, between observation units are meaningful representations of discrepancies of values, these discrepancies generally being a major reason for constructing a cartogram”
  2. production of noncontiguous cartograms involves “only the discrete units for which information is available and only the lines which can be accurately relocated on the original map appear on the noncontiguous cartogram”
  3. because of perfect shape preservation, “recognition of the units represented is relatively uncomplicated for the reader”

Despite these inherent advantages (along with ease of production), all the early value-by-area cartograms I’ve seen maintain contiguity. Some took the radical step of abstracting features to geometric primitives, like Levasseur’s early French examples (which may not have been cartograms) and Erwin Raisz’s early American “rectangular statistical cartograms”. But in many ways the noncontiguous design is the more radical cartogram, as it actually breaks the basemap apart — rather than skewing shared borders it abandons them.

my [his] AS3 classes

Olson outlines a technique — the projector method — for manually producing such cartograms. A projector capable of precise numeric reduction/enlargement was required, but not much else, and accurate cartograms could be produced in minutes. A scaling factor was calculated for each enumeration unit, the projector was set to this value, and the projected borders were traced, keeping units centered on their original centers.

My [his] AS3 NoncontiguousCartogram class works similarly. It takes an array of objects containing geometry and attribute properties and creates a noncontiguous cartogram. I include methods for creating the input array from a shapefile/dbf combo, but using KML, WKT, or geoJSON representations wouldn’t be too hard. Methods are included for projecting this lat/long linework (to Lambert’s Conformal Conic projection at least). The NoncontiguousCartogram class draws the input geography, figures the area of each feature, and scales figures according to their density in the chosen thematic variable.

It’s all good/in ActionScript 3, so can be used in Flash or Flex. The zip distribution includes the following:

  • the main class
  • two example applications and the data needed to run them
  • utility classes, including some that make creating cartograms from shp/dbf input quite easy
  • Edwin Van Rijkom’s SHP and DBF libraries, which are used to load the shapefiles in both of the included examples
  • Keith Peters’ MinimalComps AS3 component library, for the components used in one of the examples
  • Grant Skinner’s gTween class, which is required by the NoncontiguousCartogram class for tween transitions

Browse all the above or download the zip.


more advantages

In my thesis research last spring, noncontiguous cartograms performed quite well: subjects rated them highly on aesthetics and could locate and estimate the areas of features with relatively high accuracy. I would add the following to Olson’s list of noncontiguous cartogram advantages.

  1. Olson concentrates on the perfect shape preservation of noncontiguous cartograms. The form (well, those with units centered on the original enumeration unit centroids, as in Olson’s projector method) also perfectly preserves the location of the features on the resultant transformed cartogram. Not only are features easier to recognize, but locations within the transformed units can be accurately located as well (cities or mountain ranges from the original geography can be accurately plotted on the transformed cartogram).
  2. Because units are separate on the transformed cartogram, their figure-ground is increased and areas of features can therefore be more accurately estimated.
  3. Many cartogram designs (including most manual cartograms and the Gastner-Newman-produced cartograms) sacrifice some accuracy for shape recognition. This is a defensible tradeoff, especially as area estimation is notoriously inaccurate and nonlinear. Yet it’s a tradeoff that noncontigous cartograms need not make, as they can always perfectly represent the data with relative areas without sacrificing shape preservation.

Thus, noncontiguous cartograms seem to excel at the cartogram’s two main map-reading tasks: shape recognition and area estimation. This is mediated somewhat by the chief advantage of contiguous cartograms: compactness. Because no space is created between enumeration units, contiguous cartogram enumeration units can be larger than those on noncontiguous cartograms, all other things equal. The increased size on contiguous cartograms may improves their legibility.

Read the full entry over at Indie Maps . . .