Category Archives for Blog

Combining Choropleth Maps and Reference Maps in R

Recent updates to my mapping packages now make it easy to combine choropleth maps and reference maps in R. All you have to do is pass the parameter reference_map = TRUE to the existing functions. This should “just work”, regardless of which region you zoom in on or what data you display. The following table shows the affected functions and their […]

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User Question: How to Add a State Border to a Zip Code Map?

A user recently asked me how to add a state outline to a Zip Code map. Consider this map, which shows the percent white of each Zip Code Tabulated Area (ZCTA) in New York and New Jersey: Clearly the ZCTAs in northern New York have the highest concentration of white residents. However, it would still […]

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New Lesson: Mapping Historic Census Data in R

Today I am happy to announce a new lesson for my free email course Learn to Map Census Data in R. This lesson explains how to get and map historic census data in R. While I had intended this lesson to only go to new signups, it looks like my email provider sent it (along […]

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Free R Help

Today I am giving away 10 sessions of free, online, one-on-one R help. My hope is to get a better understanding of how my readers use R, and the issues they face when working on their own projects. The sessions will be over the next two weeks, online and 30-60 minutes each. I just purchased Screenhero, […]

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New release: Choroplethr v3.2.0

Today I am happy to announce that a new version of choroplethr, v3.2.0, is now available. You can get it by typing the following from an R console: install.packages(“choroplethr”) Note that it sometimes takes a few days for new packages to get copied to each CRAN mirror. If install.packages(“choroplethr”) only gets you version 3.1.0, please try again tomorrow. […]

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How to Remove State Abbreviations from a Choroplethr Map

Today I will demonstrate how to remove state abbreviations from a choroplethr map. I will also demonstrate how to combine multiple maps into a single image. This is what the final image looks like: In this case the abbreviations obscure information for the northeast part of the country, so it’s useful to remove them. Step […]

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Mapping Historic US Presidential Election Results

Today I will demonstrate how to map historic US Presidential Election results in R. If you want to skip ahead and play with a shiny app that lets you visualize this dataset, then click here. The dataset we will use comes from wikipedia’s List of United States presidential election results by state and is packaged in the choroplethr […]

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Tutorial Recap: Make a Census Explorer with Shiny

On July 28 I had the pleasure of leading a tutorial titled Make a Census Explorer with Shiny! at the San Francisco R-ladies Meetup. A big thank you to Gabriela de Queiroz for organizing the event, Sharethrough for hosting it, and all the participants for attending. If you are interested in seeing the slides, you […]

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Administrative Maps and Projections in R

Today I will demonstrate how to create maps of “other countries”, and use map projections, with the choroplethr package in R. I write “other countries” in quotes because, like most things, translating a high level wish into software can be complicated. If you want to skip ahead and play with a web app that lets you explore […]

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New Tutorial: Make a Census Explorer!

Today I am happy to announce a new tutorial I am running titled Make a Census Explorer with Shiny! It is free and will be held July 28 in San Francisco. In the tutorial we will combine R’s Shiny framework for web development with the census-mapping choroplethr package to create a browser-based census explorer. You can see the final app here. Here […]

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