R makes it easy to add squares and rectangles to your plots, but it gets a little tricky when you have a bunch to draw at once. The key is to break it down to the elements.
R

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Drawing Squares and Rectangles in R

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Voronoi Diagram and Delaunay Triangulation in R
The
deldir
package by Rolf Turner makes the calculations and plotting straightforward, with a few lines of code. 
Comparing ggplot2 and R Base Graphics
Figure out which is best with a sidebyside comparison.

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Adding Legends in R
Make sure you explain your visual encodings so that others can interpret them.

Emergency room data in R
For my graphic on emergency room visits over time and the other on…

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How to Customize Axes in R
For presentation purposes, it can be useful to adjust the style of your axes and reference lines for readability. It’s all about the details.

R growth on StackOverflow reigns supreme
Joshua Kunst did a quick analysis on tag usage on StackOverflow, the question…

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How to Make an Animated Pyramid Chart in R
Make a bunch of charts, string them together like a flip book, and there’s your animation. Sometimes good for showing changes over time. Always fun to play with.

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How to Make Bivariate Area Charts in R
Quickly compare two time series variables with this linearea chart hybrid that originated in the 1700s. Also known as: difference chart.

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How to Make Maps in R That Include Alaska and Hawaii
The conterminous United States always gets the attention, while Alaska and Hawaii are often left out. It is time to bring them back into view.

Tufte style charts in R
Lukasz Piwek is chipping away at a collection of Tuftestyle charts using R,…

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How to Map and Use GeoTIFF Files in R
It’s like working with a bunch of tiny dots, and oh look, all of sudden patterns emerge.

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How to Make Horizon Graphs in R
The relatively new and lesser known time series visualization can be useful if you know what you’re looking at, and they take up a lot less space.

R Consortium for further development of community
The Linux Foundation announced the R Consortium to provide support to the R…

Working with R at the New York Times
Amanda Cox from the New York Times was on the Data Stories podcast.…

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How to Make Variable Width Bar Charts in R
The code to create these bar chart variations is almost the same as if you were to make a standard bar chart. But make sure you get the math right.

R is quirky, flawed, and an enormous success
Most people who use R on the regular learned the language in the…

Length of the average master’s thesis
A while back beckmw found the average length of a dissertation for various…

A Course for Visualization in R, Taking You From Beginner to Advanced
Where to start? What to learn next? Here’s a course to help take you from beginner to advanced.

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How to Make Dot Plots in R
It’s easy to draw dots. The challenge is to make them meaningful and readable.