Basics of R

Find the solution to these exercises without using R.

Exercise 1: Write the output.

4:8
Answer

4 5 6 7 8

Exercise 2: Write the output.

3 * c(3, 4)
Answer

9 12

Exercise 3: Write the output.

sqrt(25)
Answer

5

Exercise 4: Write the output.

hello <- 6
Hello <- 4
hello
Answer

6

Exercise 5: Solve the problem.

round(sum(vector)
Answer

it lacks the last parenthesis )

Exercise 6: Solve the problem.

data.frame(country = c("Germany", "Argentina", "China"),
           lifeexp = c(81.2, 76.2, 73.1)
Answer

it lacks the last parenthesis )

Exercise 7: Solve the problem(s).

country <- c("Germany". "Argentina", "China"),
lifeexp <- c(81.2, 76.2, 73.1)
data.frame(country, lifexp)
Answer

a point separates Germany and Argentina
the comma at the end of the first line should be removed in the last row, it lacks an ‘e’ in lifexp

Exercise 8: Write the output.

c(TRUE, 4)
Answer

1 4

Exercise 9: Does this produce a character, numeric or logical vector?

c(TRUE, 4)
Answer

numeric vector

Exercise 10: What is the output of the following code?

c(FALSE, "One", 2)
Answer

“FALSE” “One” “2”

Exercise 11: Does this produce a character, numeric or logical vector?

c(FALSE, "One", 2)
Answer

character vector

Exercise 12: Write the output.

numbers <- c(10,6,12,17,5)
numbers[3,5]
Answer

12 5

Exercise 13: Write the output.

numbers <- c(3,22,4,23,5)
numbers[2:3]
Answer

22 4

Exercise 14: Which rows and columns do we select?

dataframe[c(1,4), ]
Answer

1st and 4th row, all columns

Exercise 15: Which rows and columns do we select?

dataframe[ ,"country"]
Answer

All rows, the column named “country”

Exercise 16: Write the output.

numbers <- c(3.55, 4.99, 5.62)
round(numbers)
Answer

4 5 6

Exercise 17: Write the output.

max(c(3.55, 4.99, 5.62))
Answer

5.62

Exercise 18: Write the output.

max(sum(c(3.5, 6.5)))
sum(max(c(3.5, 6.5)))
Answer

10 6.5

Exercise 19: Write the output.

as.numeric(c(FALSE, TRUE))
Answer

0 1

Exercise 20: Write the output.

as.integer(6.2)
Answer

6

Exercise 21: Write the output.

as.integer(factor(c("Argentina", "Zambia", "Congo")))
Answer

1 3 2

Exercise 22: Write the output.

end <- c(5, 9, 3)  
as.numeric(end > 6)
Answer

0 1 0

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