Category: R

Zenguo Zhang teaches a lesson:

In ggplot2, when displaying grouped data along categorical axes (such as grouped bar charts, boxplots, or error bars), horizontal dodging is used to prevent elements from overlapping at each categorical position. ggplot2 provides two primary dodging position functions: position_dodge() and position_dodge2().

Click through or else Piccolo is going to yell again.

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Thomas Williams has a script:

DBAs spend time dealing with SQL Server performance, capacity, monitoring, troubleshooting, provisioning, etcetera; I’ve previously mentioned that R is a powerful, open-source language with a great ecosystem of libraries for analysis and visualisation, so it’s no surprise that I think mixing SQL Server and R Markdown for reporting goes together like a Vegemite and cheese sandwich…lunch perfection!

Here’s a couple of real-world examples of how I’ve used R Markdown connected to SQL Server (for a recap of how to do this from a technical perspective, see my earlier blog post “Connecting to a SQL Server database from R Markdown”):

This is a neat approach to visualizing database backup times as a process control chart.

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Andrea Onofri builds a complex chart:

I have often found myself needing to plot a single graph with two y-axes having different scales. For example, this might be useful for representing temperature and rainfall data at a given location. Unfortunately, doing this with ggplot() is not straightforward.

As Andrea mentions, there are specific circumstances in which having a dual-axis chart is reasonable, and click through to learn how. ggplot2 tends to be rather opinionated regarding visual choice and design. I happen to like those opinions and think they are generally correct, but I can also recognize that there may be exceptions to the rules. For those instances, I think “Somewhat difficult but not impossible” is a solid answer, as it keeps people from doing things inappropriately with a couple of mouse clicks, like setting up those stupid 3D bar charts in Excel. H/T R-Bloggers.

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Mauricio Vargas Sepulveda has released an R package:

The goal of spuriouscorrelations is to keep alive the amazing examples from Tyler Vigen. Unfortunately, as of 2023-10-09, the website is down as my students noticed. Therefore, I decided to use the snapshot from the Internet Wayback Machine to save the datasets from 2023-06-07.

Click through to see how you can re-live those old charts, using the example of “number of people who drowned by falling into a pool” versus “films Nicolas Cage appeared in” on an annual basis. H/T R-Bloggers.

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Thomas Williams is back with more:

In my last post on improving inputs in R Markdown/Shiny, I covered four improvements to quality of life in interactive reports and dashboards. In this blog post I have three more, all approaches I’ve used to add professionalism to self-service R Markdown files.

In yet another plug for R Markdown: most of these techniques can be used in a single *.Rmd file, or can be included in many by putting them in a common CSS or javascript file and linking to it.

Click through to see what you can do.

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