From 74a480e5d6a9887802747dbfbf88e38336411b07 Mon Sep 17 00:00:00 2001 From: hadley Date: Wed, 3 May 2017 08:00:32 -0500 Subject: [PATCH] Move exercise to better location #514 --- transform.Rmd | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/transform.Rmd b/transform.Rmd index 6eb3513..9986a2f 100644 --- a/transform.Rmd +++ b/transform.Rmd @@ -831,10 +831,6 @@ daily %>% effects of bad airports vs. bad carriers? Why/why not? (Hint: think about `flights %>% group_by(carrier, dest) %>% summarise(n())`) -1. For each plane, count the number of flights before the first delay - of greater than 1 hour. (Hint: read about cummulative window functions and - see how their negations work, `vignette("window-functions")`) - 1. What does the `sort` argument to `count()` do. When might you use it? ## Grouped mutates (and filters) @@ -896,3 +892,6 @@ Functions that work most naturally in grouped mutates and filters are known as 1. Find all destinations that are flown by at least two carriers. Use that information to rank the carriers. + +1. For each plane, count the number of flights before the first delay + of greater than 1 hour.