5.1 Atomic Vectors

#Creates a vector named die that contains six numeric elements
die <- c(1, 2, 3, 4, 5, 6)
die
## [1] 1 2 3 4 5 6
#Tests whether the object is an atomic vector
is.vector(die)
## [1] TRUE
#Creates a vector with only 1 value
five <- 5
five
## [1] 5
#Tests whether the object is an atomic vector
is.vector(five)
## [1] TRUE
#Returns the length of the vector
length(five)  
## [1] 1
#Returns the length of the vector
length(die)  
## [1] 6
#Creates an integer vector
int <- 1L

#Creates a character vector
text <- "ace"
#Creates an integer vector
int <- c(1L, 5L)

#Creates a character vector
text <- c("ace", "hearts")
#Calculates the sum of vector "int"
sum(int)
## [1] 6
#Calculates the sum of vector "text" - will returns error
#sum(text)

5.1.1 Doubles

#Creates a vector named die that contains six numeric elements
die <- c(1, 2, 3, 4, 5, 6)
die
## [1] 1 2 3 4 5 6
#Identifies the type of an object
typeof(die)
## [1] "double"

5.1.2 Integers

#Creates an integer vector
int <- c(-1L, 2L, 4L) 
int
## [1] -1  2  4
#Identifies the type of an object
typeof(int)
## [1] "integer"
#Demonstrates a situation when R does not return zero as we normally expected
sqrt(2)^2 - 2
## [1] 4.440892e-16

5.1.3 Characters

#Creates a character vector
text <- c("Hello",  "World")
text
## [1] "Hello" "World"
#Returns type of an object
typeof(text)
## [1] "character"
#Returns type of an element in the "text" vector
typeof("Hello")
## [1] "character"

5.1.4 Logicals

#Logicals - returns TRUE or FALSE
3 > 4
## [1] FALSE
#Creates a logical vector
logic <- c(TRUE, FALSE, TRUE)
logic
## [1]  TRUE FALSE  TRUE
#Returns type of an object
typeof(logic)
## [1] "logical"
#Returns type of an element in the "logic" vector
typeof(F)
## [1] "logical"

5.1.5 Complex and Raw

#Creates a complex vector
comp <- c(1 + 1i, 1 + 2i, 1 + 3i)
comp
## [1] 1+1i 1+2i 1+3i
#Returns type of an object
typeof(comp)
## [1] "complex"
#Creates a raw vector
raw(3)
## [1] 00 00 00
#Returns type of the vector
typeof(raw(3))
## [1] "raw"
Exercise 5.2 (Vector of Cards)
#Creates a character vector
hand <- c("ace", "king", "queen", "jack", "ten")
hand
## [1] "ace"   "king"  "queen" "jack"  "ten"
#Returns type of an object
typeof(hand)
## [1] "character"

5.3 Matrices

#Creates a 2-row matrix using vector "die"
m <- matrix(die, nrow = 2)
m
##      [,1] [,2] [,3]
## [1,]    1    3    5
## [2,]    2    4    6
#Creates a similar matrix as above using vector "die" but filling by row
m <- matrix(die, nrow = 2, byrow = TRUE)
m
##      [,1] [,2] [,3]
## [1,]    1    2    3
## [2,]    4    5    6

5.4 Arrays

#Creates a 3-dimensional array
ar <- array(c(11:14, 21:24, 31:34), dim = c(2, 2, 3))
ar
## , , 1
## 
##      [,1] [,2]
## [1,]   11   13
## [2,]   12   14
## 
## , , 2
## 
##      [,1] [,2]
## [1,]   21   23
## [2,]   22   24
## 
## , , 3
## 
##      [,1] [,2]
## [1,]   31   33
## [2,]   32   34
Exercise 5.3 (Make a Matrix)
#Creates a character vector
hand1 <- c("ace", "king", "queen", "jack", "ten", "spades", "spades", 
  "spades", "spades", "spades")

#Turns the character vector into a matrix via three different commands
matrix(hand1, nrow = 5)
##      [,1]    [,2]    
## [1,] "ace"   "spades"
## [2,] "king"  "spades"
## [3,] "queen" "spades"
## [4,] "jack"  "spades"
## [5,] "ten"   "spades"
matrix(hand1, ncol = 2)
##      [,1]    [,2]    
## [1,] "ace"   "spades"
## [2,] "king"  "spades"
## [3,] "queen" "spades"
## [4,] "jack"  "spades"
## [5,] "ten"   "spades"
dim(hand1) <- c(5, 2)
#Repeats the exercise above but in a different way
#Creates a character vector in a different order
hand2 <- c("ace", "spades", "king", "spades", "queen", "spades", "jack", 
  "spades", "ten", "spades")

#Turns the character vector into a matrix via two different commands
matrix(hand2, nrow = 5, byrow = TRUE)
##      [,1]    [,2]    
## [1,] "ace"   "spades"
## [2,] "king"  "spades"
## [3,] "queen" "spades"
## [4,] "jack"  "spades"
## [5,] "ten"   "spades"
matrix(hand2, ncol = 2, byrow = TRUE)
##      [,1]    [,2]    
## [1,] "ace"   "spades"
## [2,] "king"  "spades"
## [3,] "queen" "spades"
## [4,] "jack"  "spades"
## [5,] "ten"   "spades"

5.7 Lists

#Creates a list containing two vectors and a list
list1 <- list(100:130, "R", list(TRUE, FALSE))
list1
## [[1]]
##  [1] 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118
## [20] 119 120 121 122 123 124 125 126 127 128 129 130
## 
## [[2]]
## [1] "R"
## 
## [[3]]
## [[3]][[1]]
## [1] TRUE
## 
## [[3]][[2]]
## [1] FALSE
Exercise 5.5 (Use a List to Make a Card)
#Creates a list to store a playing card with the ace of hearts and a point value of one
card <- list("ace", "hearts", 1)
card
## [[1]]
## [1] "ace"
## 
## [[2]]
## [1] "hearts"
## 
## [[3]]
## [1] 1

5.8 Data Frames

#Creates a data frame
df <- data.frame(face = c("ace", "two", "six"),  
  suit = c("clubs", "clubs", "clubs"), value = c(1, 2, 3))
df
##   face  suit value
## 1  ace clubs     1
## 2  two clubs     2
## 3  six clubs     3
#Gives names to a list
list(face = "ace", suit = "hearts", value = 1)
## $face
## [1] "ace"
## 
## $suit
## [1] "hearts"
## 
## $value
## [1] 1
#Gives names to a vector
c(face = "ace", suit = "hearts", value = "one")
##     face     suit    value 
##    "ace" "hearts"    "one"
#Returns type of "df"
typeof(df)
## [1] "list"
#Returns class of "df"
class(df)
## [1] "data.frame"
#Returns types of objects that are grouped together
str(df)
## 'data.frame':    3 obs. of  3 variables:
##  $ face : chr  "ace" "two" "six"
##  $ suit : chr  "clubs" "clubs" "clubs"
##  $ value: num  1 2 3
#Prevents R from saving character strings as factors
df <- data.frame(face = c("ace", "two", "six"),  
  suit = c("clubs", "clubs", "clubs"), value = c(1, 2, 3),
  stringsAsFactors = FALSE)
#Creates a data frame to build an entire deck of cards
deck <- data.frame(
  face = c("king", "queen", "jack", "ten", "nine", "eight", "seven", "six",
    "five", "four", "three", "two", "ace", "king", "queen", "jack", "ten", 
    "nine", "eight", "seven", "six", "five", "four", "three", "two", "ace", 
    "king", "queen", "jack", "ten", "nine", "eight", "seven", "six", "five", 
    "four", "three", "two", "ace", "king", "queen", "jack", "ten", "nine", 
    "eight", "seven", "six", "five", "four", "three", "two", "ace"),  
  suit = c("spades", "spades", "spades", "spades", "spades", "spades", 
    "spades", "spades", "spades", "spades", "spades", "spades", "spades", 
    "clubs", "clubs", "clubs", "clubs", "clubs", "clubs", "clubs", "clubs", 
    "clubs", "clubs", "clubs", "clubs", "clubs", "diamonds", "diamonds", 
    "diamonds", "diamonds", "diamonds", "diamonds", "diamonds", "diamonds", 
    "diamonds", "diamonds", "diamonds", "diamonds", "diamonds", "hearts", 
    "hearts", "hearts", "hearts", "hearts", "hearts", "hearts", "hearts", 
    "hearts", "hearts", "hearts", "hearts", "hearts"), 
  value = c(13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 13, 12, 11, 10, 9, 8, 
    7, 6, 5, 4, 3, 2, 1, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 13, 12, 11, 
    10, 9, 8, 7, 6, 5, 4, 3, 2, 1)
)
deck
##     face     suit value
## 1   king   spades    13
## 2  queen   spades    12
## 3   jack   spades    11
## 4    ten   spades    10
## 5   nine   spades     9
## 6  eight   spades     8
## 7  seven   spades     7
## 8    six   spades     6
## 9   five   spades     5
## 10  four   spades     4
## 11 three   spades     3
## 12   two   spades     2
## 13   ace   spades     1
## 14  king    clubs    13
## 15 queen    clubs    12
## 16  jack    clubs    11
## 17   ten    clubs    10
## 18  nine    clubs     9
## 19 eight    clubs     8
## 20 seven    clubs     7
## 21   six    clubs     6
## 22  five    clubs     5
## 23  four    clubs     4
## 24 three    clubs     3
## 25   two    clubs     2
## 26   ace    clubs     1
## 27  king diamonds    13
## 28 queen diamonds    12
## 29  jack diamonds    11
## 30   ten diamonds    10
## 31  nine diamonds     9
## 32 eight diamonds     8
## 33 seven diamonds     7
## 34   six diamonds     6
## 35  five diamonds     5
## 36  four diamonds     4
## 37 three diamonds     3
## 38   two diamonds     2
## 39   ace diamonds     1
## 40  king   hearts    13
## 41 queen   hearts    12
## 42  jack   hearts    11
## 43   ten   hearts    10
## 44  nine   hearts     9
## 45 eight   hearts     8
## 46 seven   hearts     7
## 47   six   hearts     6
## 48  five   hearts     5
## 49  four   hearts     4
## 50 three   hearts     3
## 51   two   hearts     2
## 52   ace   hearts     1