In c403: Exam Tools for Department of Statistics (c403), Uni Innsbruck

# Create a random integer vector of length 5
x <- sample(1:100, 5)
# Ask for the following index between 1:5
idx <- sample(1:5, 1)
# Wrong answers
wrong <- sample((1:5)[-idx], 2)
# The correct answer:
res <- x[idx]

Question

Vector subsetting in R. We can access elements/values in a vectur using vector subsetting by index. Imagine we have the following vector x:

print(x)

If we call x[r idx], what is the resulting value?

Answerlist

• We get r x[wrong[1L]]
• We get r x[wrong[2L]]
• We get r x[idx]

Solution

x[r idx] returns the r idxth element of the vector x which is r x[idx].

Answerlist

• False
• False
• Correct

Meta-information

exname: Vector subsetting extype: schoice exsolution: 001 exshuffle: True

c403 documentation built on Oct. 20, 2023, 3:01 p.m.