Pipelines in R are popular, the most popular one being magrittr as used by dplyr.
This note will discuss the advanced re-usable piping systems: rquery/rqdatatable operator trees and wrapr function object pipelines. In each case we have a set of objects designed to extract extra power from the wrapr dot-arrow pipe %.>%.
In our wrapr pipe RJournal article we used piping into ggplot2 layers/geoms/items as an example.
Being able to use the same pipe operator for data processing steps and for ggplot2 layering is a question that comes up from time to time (for example: Why can’t ggplot2 use %>%?). In fact the primary ggplot2 package author wishes that magrittr piping was the composing notation for ggplot2 (though it is obviously too late to change).
There are some fundamental difficulties in trying to use the magrittr pipe in such a way. In particular magrittr looks for its own pipe by name in un-evaluated code, and thus is difficult to engineer over (though it can be hacked around). The general concept is: pipe stages are usually functions or function calls, and ggplot2 components are objects (verbs versus nouns); and at first these seem incompatible.
However, the wrapr dot-arrow-pipe was designed to handle such distinctions.
Let’s work an example.
We are thrilled to announce our (my and Nina Zumel’s) paper on the dot-pipe has been accepted by the R-Journal!
Continue reading Dot-Pipe Paper Accepted by the R Journal!!!