The “grammar of tables” is used to build tables with the R-package gt. Thomas Mock published an extension package called gtExtras which is used all over in tweets about NFL and Fantasy Football such as win and loss history information in a table.

gt follows a similar philosophy such as ggplot2. On the one hand there is the data to be shown (in a table resp. a plot). On the other hand there is the description how to visualize the data: What is the table header, are there subheaders, how are the cells grouped and formated?

So it was time to check out gt. During my tryouts I came across one demand I haven’t found an in-built solution for: I wanted to format a column with respect to the value of another column. Here’s the way I solved it:

Last weekend I fixed some issues with my R-package piwikproR

The new version 0.3.1 is now available at CRAN

So let’s have a look at the changes:

Lately I tried to visualize an hierarchy with Tableau Desktop. The problem was that the hierarchy had a variable depth because it was tree-based. Each row had an id and a parent_id. Normally hierarchies in Tableau are defined by pulling some fields together, such as product category, product group and product id.

Handling tree-based hierarchies seems to be a lot more complex. I found a plugin at https://github.com/tableau/extension-hierarchy-navigator-sandboxed but this only works online.

So I asked myself how I can handle this using R. I found the R-package data.tree at https://github.com/gluc/data.tree. I want to describe how I use this package to preprocess my data.

Sometimes you generate lots of ggplots of a similar kind, e.g. visualizations of different timeseries. Then you want to highlight some dates where something special had happened and you want to show that the value you are plotting changed at these dates.

So it would be nice if we can refactor these geom_vline or geom_hline calls into one single function.

You know it, I’m sure: You are developing a data transformation using lots of pipes. Then you need to remove one or more lines. You do this using comments.

So far so good. But if it’s the last line you want to remove a simple comment will produce an error because of the trailing pipe symbol at the end of the second to last line.

Here’s a solution: