R Programming Language Multiple Choice Questions on “Basics”.
1. The most convenient way to use R is at a graphics workstation running a ________ system.
a) windowing
b) running
c) interfacing
d) matrix
Answer: a
Clarification: Most classical statistics and much of the latest methodology is available for use with R.
2. Point out the wrong statement?
a) Setting up a workstation to take full advantage of the customizable features of R is a straightforward thing
b) q() is used to quit the R program
c) R has an inbuilt help facility similar to the man facility of UNIX
d) Windows versions of R have other optional help systems also
Answer: b
Clarification: help command is used for knowing details of particular command in R.
3. Which of the following is default prompt for UNIX environment?
a) >
b) >>
c) <
d) <<
Answer: a
Clarification: When you use the R program it issues a prompt when it expects input commands.
4. Which of the following will start the R program?
a) $ R
b) > R
c) * R
d) @ R
Answer: a
Clarification: At this point R commands may be issued.
5. Point out the wrong statement?
a) Windows versions of R have other optional help system also
b) The help.search command (alternatively ??) allows searching for help in various ways
c) R is case insensitive as are most UNIX based packages, so A and a are different symbols and would refer to different variables
d) $ R is used to start the R program
Answer: c
Clarification: R is an expression language with a very simple syntax.
6. Which of the following statement is alternative to _________
?solve
a) help(solve)
b) print(solve)
c) bind(solve)
d) matrix(solve)
Answer: a
Clarification: help is used to get more information on any specific named function.
7. Elementary commands in R consist of either _______ or assignments.
a) utilstats
b) language
c) expressions
d) packages
Answer: c
Clarification: If an expression is given as a command, it is evaluated, printed (unless specifically made invisible), and the value is lost.
8. If a command is not complete at the end of a line, R will give a different prompt, by default it is ____________
a) *
b) –
c) +
d) /
Answer: c
Clarification: Comments can be put almost anywhere, starting with a hashmark (‘#’), everything to the end of the line is a comment.
9. Command lines entered at the console are limited to about ________ bytes.
a) 3000
b) 4095
c) 5000
d) 6000
Answer: b
Clarification: Elementary commands can be grouped together into one compound expression by braces (‘{’ and ‘}’).
10._____ text editor provides more general support mechanisms via ESS for working interactively with R.
a) EAC
b) Emacs
c) Shell
d) ECAP
Answer: b
Clarification: The recall and editing capabilities under UNIX are highly customizable.