Exercise

Datetimes behave nicely too

Just like Date objects, you can plot and do math with POSIXct objects.

As an example, in this exercise you'll see how quickly people download new versions of R, by examining the download logs from the RStudio CRAN mirror.

R 3.2.0 was released at "2015-04-16 07:13:33" so cran-logs_2015-04-17.csv contains a random sample of downloads on the 16th, 17th and 18th.

Instructions

100 XP
  • Use read_csv() to import cran-logs_2015-04-17.csv.
  • Print logs to see the information we have on each download.
  • Store the R 3.2.0 release time as a POSIXct object.
  • Find out when the first request for 3.2.0 was made by filtering for values in the datetime column that are greater than release_time.
  • Finally see how downloads increase by creating histograms of download time for 3.2.0 and the previous version 3.1.3. We've provided most of the code, you just need to specify the x aesthetic to be the datetime column.