Blog Archives

Mapping Public Opinion: A Tutorial

July 18, 2012
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Mapping Public Opinion: A Tutorial

At the upcoming 2012 summer meeting of the Society of Political Methodology, I will be presenting a poster on Isarithmic Maps of Public Opinion. Since last posting on the topic, I have made major improvements to the code and robustness of the modeling approach, and written a tutorial that illustrates the production of such maps. This … Read more

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Isarithmic Maps of Public Opinion Data

October 24, 2011
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Isarithmic Maps of Public Opinion Data

As a follow-up to my isarithmic maps of county electoral data, I have attempted to experiment with extending the technique in two ways. First, where the electoral maps are based on data aggregated to the county level, I have sought to generalize the method to accept individual responses for which only zip code data is … Read more

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Choropleth tutorial and regression coefficient plots

February 21, 2011
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Choropleth tutorial and regression coefficient plots

About two weeks ago, I gave short talk at Duke, wherein I presented a brief tutorial on creating choropleth maps in R using ggplot2. Since the code is already written, and the data and shapefiles already hosted online, I thought I would share the tutorial more widely. A .ZIP file containing all the files necessary … Read more

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Electoral Marimekko Plots

December 6, 2010
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Electoral Marimekko Plots

To be reductive, visual displays of quantitative information might be reasonably categorized on a continuum between “data display” and “statistical graphics.” By statistical graphics, I mean a plot that displays some summary of or relationship amongst several variables, likely having undergone some processing or analysis. This may be as simple as a scatterplot of a … Read more

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Isarithmic History of the Two-Party Vote

November 15, 2010
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Isarithmic History of the Two-Party Vote

A few weeks ago, I shared a series of choropleth maps of U.S. presidential election returns, illustrating the relative support for Democratic, Republican, and third Party candidates since 1920. The granularity of these county level results led me to wonder whether it would be possible to develop an isarithmic map of presidential voting using the … Read more

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Choropleth Maps of Presidential Voting

November 1, 2010
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Choropleth Maps of Presidential Voting

Having always appreciated the red and blue cartograms and cartographs of geographic electoral preferences, such as those made available by Mark Newman, I sought to produce similar maps, but include information about support for non-”state-sponsored” parties, and to extend the coverage back in time. I was able to find county-level presidential election returns going as … Read more

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K-Means Redistricting

October 18, 2010
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K-Means Redistricting

U.S. Congressional districts are today drawn with the aim of maximizing the electoral advantage of the state’s majority party, subject to some constraints, including compactness (which can be measured in numerous ways) and a “one person, one vote” standard. What if, instead of minimizing population variance across districts, we aimed to minimize the mean distance between … Read more

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