From 4795d093bc90ac702f9f034180097e93acc6c8ca Mon Sep 17 00:00:00 2001 From: Hadley Wickham Date: Sun, 18 Sep 2022 16:23:42 -0500 Subject: [PATCH] Add warning message to joins chapter --- joins.qmd | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/joins.qmd b/joins.qmd index 7999006..5c5f507 100644 --- a/joins.qmd +++ b/joins.qmd @@ -25,6 +25,11 @@ If you're familiar with SQL, you should find the ideas in this chapter familiar, ### Prerequisites +::: callout-important +This chapter relies on features only found in the development version of dplyr. +If you want to live life on the edge you can get the dev version with `devtools::install_github("tidyverse/dplyr")`. +::: + We'll explore the five related datasets from nycflights13 using the join functions from dplyr. ```{r} @@ -329,7 +334,8 @@ airports |> ``` **Anti-joins** are the opposite: they return all rows in `x` that don't have a match in `y`. -They're useful for finding missing values that are **implicit** in the data, the topic of @sec-missing-implicit. Implicitly missing values don't show up as explicit `NA`s but instead only exist as an absence. +They're useful for finding missing values that are **implicit** in the data, the topic of @sec-missing-implicit. +Implicitly missing values don't show up as explicit `NA`s but instead only exist as an absence. For example, we can find rows that should be in `airports` by looking for flights that don't have a matching destination: ```{r}