Merge branch 'master' of github.com:hadley/r4ds

relational-data.Rmd

@@ -452,7 +452,7 @@ flights %>%
     patterns?
 
 1.  What does `anti_join(flights, airports, by = c("dest" = "faa"))` tell you?
-    What does `anti_join(airports, flights, by = c("dest" = "faa"))` tell you?
+    What does `anti_join(airports, flights, by = c("faa" = "dest"))` tell you?
 
 ## Join problems
 

transform.Rmd

@@ -598,7 +598,7 @@ delays <- flights %>%
     dist = mean(distance, na.rm = TRUE),
     delay = mean(arr_delay, na.rm = TRUE)
   ) %>% 
-  filter(delay, count > 20, dest != "HNL")
+  filter(count > 20, dest != "HNL")
 ```
 
 This focuses on the transformations, not what's being transformed, which makes the code easier to read. You can read it as a series of imperative statements: group, then summarise, then filter. As suggested by this reading, a good way to pronounce `%>%` when reading code is "then".