Fast reading from disk
In addition to having intelligent defaults, fread() is super fast! In this exercise, you will use the system.time() function from base R to compare the time it takes to read the batrips.csv file using read.csv() and fread(). All you need to do is pass an expression to system.time(). For example, if you want to calculate how long it takes to import a file called sample.csv, you can use:
system.time(read.csv("sample.csv"))
user system elapsed
3.495 0.040 3.547
Generally, you want to consider user time when measuring execution time. So in this case, it took 3.495 seconds to import the file sample.csv.
Cet exercice fait partie du cours
Data Manipulation with data.table in R
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
# Use read.csv() to import batrips
system.time(___("batrips.csv"))