Learning R

Appendix C. Answers to Quizzes

Question 1-1

R is an open source reworking of the S programming language.

Question 1-2

Choices include imperative, object-oriented, and functional.

Question 1-3

8:27

Question 1-4

help.search (which does the same as ??)

Question 1-5

RSiteSearch

Question 2-1

%/%

Question 2-2

all.equal(x, pi) or, even better, isTRUE(all.equal(x, pi))

Question 2-3

At least two of the following:

1. <-
2. + =
3. + <<-
4. assign

Question 2-4

Just Inf and -Inf

Question 2-5

0, Inf, and -Inf

Question 3-1

numeric, integer, and complex

Question 3-2

nlevels

Question 3-3

as.numeric("6.283185")

Question 3-4

Any three of summary, head, str, unclass, attributes, or View. Bonus points if you’ve discovered tail, the counterpart to head that prints the last few rows.

Question 3-5

rm(list = ls())

Question 4-1

seq.int(0, 1, 0.25)

Question 4-2

Either by using name = value pairs when the vector is created, or by calling the names function afterward.

Question 4-3

Positive integers for locations to retrieve, negative integers for locations to avoid, logical values, or names of elements.

Question 4-4

3 * 4 * 5 = 60

Question 4-5

%*%

Question 5-1

3. The inner list counts as one element, and so does the NULL element.

Question 5-2

When passing arguments to functions, when calling formals, or in the global environment variable .Options.

Question 5-3

You can use matrix-style indexing with pairs of positive integers/negative integers/logical values/characters in ...