Modern R Programming Cookbook

How it works…

In the step 1 from the previous section, the directory location where the CSV file and the XDF file are stored is located. Then in step 2, the read.csv() function imports the entire dataset into an R session for further processing. In step 3, using the aggregate function, the mean departure delay is calculated, and in the same step, the processing time is calculated using the system.time() function.

The processing time for each section is as follows:

    > system.time(    +   usairlineCSV <- read.csv("csv_USAairlines2016.csv")    + )       user  system elapsed      19.11    0.51   19.72

It took almost 20 seconds to read the entire CSV file into R memory. Here is the time requirement for calculating the mean:

    > system.time( + meanDelay<- with(usairlineCSV, ...