R programming

Question 1

Variables can be created using what assignment operator?

Answer 1

<- or =

Question 2

True or False (Modified)

Variables are case-sensitive

Answer 2

True

Question 3

True or False (Modified)

The data-type of the variables is determined by the type of character stored in the variable.

Answer 3

False. Type of data stored

Question 4

What are the three major data types

Answer 4

character, numeric, and logical

Question 5

It an object-oriented. A number or a result of an operation inside an object denoted by a variable.

Answer 5

Scalar

Question 6

Set elements that usually of the same type or class

Answer 6

Vector

Question 7

A unique identifier of the function

Answer 7

function-name

Question 8

required input

Answer 8

arguments

Question 9

It is a special type of vector that can contain objects of different classes.

Answer 9

List

Question 10

It occurs when different objects are mixed in vector, so that every element in the vector is of the same class

Answer 10

coercion

Question 11

vectors with a dimension attribute

Answer 11

matrices

Question 12

True or False.

a matrix is constructed column-wise. entries can be thought of starting in the upper left corner running down the columns

Answer 12

true

Question 13

Represent categorical ddata. It can be unordered or ordered.

Answer 13

factor

Question 14

the nth element in a vector

Answer 14

x[n]

Question 15

specific elements in a vector x in kth, nth, mth order

Answer 15

x[c(k,n,m)]

Question 16

x[m:n]

Answer 16

the mth to nth element in vector x

Question 17

x[x>m & x<n]

Answer 17

elements between m and n

Question 18

the rth row and cth column of the x matrix

Answer 18

x[r,c]

Question 19

the 1st and 3rd row and 4th and 6th column elements of x matrix

Answer 19

x[c(1,3), c(4,6)]

Question 20

the entire rth row (including all columns)

Answer 20

x[r,]

Question 21

prints the nth member of the list

Answer 21

x[[n]]

Question 22

represented as special type of list where elements of the kist must be the same length

Answer 22

data frame

Question 23

must have every element of the same class

Answer 23

matrices

Question 24

aside from $ operator in calling variables in data frame, what is the other alternative

Answer 24

attach ()

Question 25

generates random variable(s) from the Binomial distribution (n, size, prob)

Answer 25

rbinom ()

Question 26

generates random variable(s) from the Poisson distribution (n, lambda)

Answer 26

rpos()

Question 27

generates random variable(s) from the Normal distribution (n, mean, sd)

Answer 27

rnorm()

Question 28

used to allow reproducibility of randomly generated value.

Answer 28

set.seed()

Question 29

What is abline

Answer 29

add more straight lines

Question 30

How to download packages

Answer 30

install.packages()

Question 31

executes two possible results depending on the result of a logical condition

Answer 31

if function

Question 32

take an iterator variable and assign it successive values from a sequence or a vector. It is the most used for iterating over the elements of an object (list, vector, etc.)

Answer 32

for loops

Question 33

begin by testing a condition. If it is true, then they execute the loop body. Once the loop body is executed, the condition is tested again, and so forth.

Answer 33

while loops

Question 34

True or False. Functions can be passed as arguments to other functions.

Answer 34

True

Question 35

True or False. Functions can't be nested

Answer 35

False

Question 36

the arguments included in the function definition.

Answer 36

formal arguments

Question 37

How to define a function

Answer 37

1.Function name (be specific). 2.Arguments of the function. 3.What the function does.