Exercise 1: Solutions second part

Task 2.1

Assign a new object v that is a vector with the elements c(2, 4, 5, 6, 4, -1).

v <- c(2, 4, 5, 6, 4, -1)

Task 2.2

Add 1 to each element of the vector?

v_plus_1 <- v + 1  # automatic recycling to full length
v_plus_1

[1] 3 5 6 7 5 0

Task 2.3

Swap the sign of the vector

v_swapped_sign <- -v
v_swapped_sign

[1] -2 -4 -5 -6 -4  1

Task 2.4

Get the second element of the vector

second_element <- v[2]
second_element

[1] 4

Task 2.5

Get all elements of the vector except the last one.

v_except_last1 <- v[-length(v)]
v_except_last1

[1] 2 4 5 6 4

v_except_last2 <- v[1:(length(v)-1)]
v_except_last2

[1] 2 4 5 6 4

Task 2.6

How many values of 4 does the vector contain?

count_4s <- sum(v == 4)
count_4s

[1] 2

Task 2.7

Swap the sign of all negative values.

v[v < 0] <- -v[v < 0]
v

[1] 2 4 5 6 4 1