Basics

Question 1

Open swirl package

Answer 1

library(“swirl”)

swirl()

Question 2

get current working directory

Answer 2

getwd()

Question 3

List all objects (i.e. variables) in your local workspace

Answer 3

ls()

Question 4

List all the files in your working directory

Answer 4

list.files()
or
dir()

Question 5

Determine the arguments that a function can take

Answer 5

args(function)

e.g args(list.files)

Note that it’s not args(list.files())

Question 6

Create a new directory in the current working directory

Answer 6

dir.create(“newdir”)

Question 7

Set working directory to “testdir”

Answer 7

setwd(“testdir”)

Question 8

Create a file in current working directory

Answer 8

file.create(“newfile.R”)

Question 9

Check is file exists in current working directory

Answer 9

file.exists(“file.R”)

Question 10

Access information about the file “mytest.R”

Answer 10

file.info(“mytest.R”)

Question 11

Rename “mytest.R” as “mytest2.R”

Answer 11

file.rename(“mytest.R”, “mytest2.R”)

Question 12

Make a copy of “mytest2.R” called “mytest3.R”

Answer 12

file.copy(“mytest2.R”, “mytest3.R”)

Question 13

Construct the path to a file from components in a platform-independent way

Answer 13

file. path()

e. g. file.path(“testdir2”, “testdir3”) creates testdir2/testdir3

Question 14

Remove all variables from workspace

Answer 14

rm(list=ls())

Question 15

see dataset dimensions

Answer 15

dim(dataset)

Question 16

see head of dataset

Answer 16

head(dataset)

Question 17

check the data type

Answer 17

class()