Please read on for the link to the video lecture.
TLDnW (too long, did not watch) summary: To debug an R magrittr pipeline using R and RStudio:
- Reorganize your pipeline so each pipe is at the end of the line and make all “dot” uses explicit (i.e. replace things like
map(., summary)). The diagram above illustrates this.
- Replace all
%>%“) with Bizarro pipes (“
- In RStudio “Preferences -> General” check “Show .Last.value”. This gives you a convenient view of the value of the last calculation (handy as “dot variables”, including “dot” are traditionally not shown).
You can now single step through your pipeline examining results as you go. If you hit an exception you can re-run that line again and again as the exception semantics cancel the assignment implied by the Bizarro pipe before the old value of “
.” is lost.
The “secret” to grokking the Bizarro pipe is to train your eyes to see the “
->.;” as a single atomic or indivisible glyph (ignoring the presence of “
->” and “
;“, both of which are forbidden in most style guides).
For a more detailed demonstration, please watch the video.
Data Scientist and trainer at Win Vector LLC. One of the authors of Practical Data Science with R.