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Join Dependency Sorting

In our latest installment of “R and big data” let’s again discuss the task of left joining many tables from a data warehouse using R and a system called "a join controller" (last discussed here). One of the great advantages to specifying complicated sequences of operations in data (rather than […]

Visualizing relational joins

I want to discuss a nice series of figures used to teach relational join semantics in R for Data Science by Garrett Grolemund and Hadley Wickham, O’Reilly 2016. Below is an example from their book illustrating an inner join: Please read on for my discussion of this diagram and teaching […]

The Zero Bug

I am going to write about an insidious statistical, data analysis, and presentation fallacy I call “the zero bug” and the habits you need to cultivate to avoid it. The zero bug Here is the zero bug in a nutshell: common data aggregation tools often can not “count to zero” […]