data("anscombe")
View(anscombe)
plot(y1 ~ x1, data = anscombe)
fit <- lm(y1 ~ x1, data = anscombe)
fit
## 
## Call:
## lm(formula = y1 ~ x1, data = anscombe)
## 
## Coefficients:
## (Intercept)           x1  
##      3.0001       0.5001
plot(y1 ~ x1, data = anscombe)
abline(fit, col = "red")

3 + 8 
## [1] 11
3 - 8 
## [1] -5
5 * 5 
## [1] 25
11/ 2
## [1] 5.5
2 ^ 10
## [1] 1024
11 %% 2
## [1] 1
a <- 3
b =  2
b <- 5
c <- a + b
c
## [1] 8
numer <- 17.8
class(numer)
## [1] "numeric"
char <- 'hello world' 
class(char)
## [1] "character"
logic <- TRUE
class(logic)
## [1] "logical"
card_length <- 3
card_width <- "5 inches"
class(card_length)
## [1] "numeric"
class(card_width)
## [1] "character"
#card_length * card_width

card_width <- 5
card_length * card_width
## [1] 15
RRP <- 35.99
Exchange <- 31.74
RRP
## [1] 35.99
NTD <- RRP * Exchange
NTD
## [1] 1142.323

向量

height_vec <- c(180, 169, 173)
height_vec[1]
## [1] 180
height_vec[3]
## [1] 173
height_vec[c(1,3)]
## [1] 180 173
name_vec <- c("Brian", 'Toby', 'Sherry')

x <- c(1,2,3,7)
y <- c(2,3,5,1)

x + y
## [1] 3 5 8 8
x * y
## [1]  2  6 15  7
x - y
## [1] -1 -1 -2  6
x / y
## [1] 0.5000000 0.6666667 0.6000000 7.0000000
students <- c(44, 52, 60, 38, 19)
students + 30 
## [1] 74 82 90 68 49
students + c(30)
## [1] 74 82 90 68 49
students + c(30,30 ,30, 30 ,30)
## [1] 74 82 90 68 49
1:20
##  [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20
x <- 1:20
y <- seq(1, 20, by=2)
y
##  [1]  1  3  5  7  9 11 13 15 17 19
?seq
## starting httpd help server ...
##  done
students <- c(44, 52, 60, 38, 19)
sum(students)
## [1] 213
sum(students) / 5
## [1] 42.6
mean(students)
## [1] 42.6
max(students)
## [1] 60
min(students)
## [1] 19
summary(students)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    19.0    38.0    44.0    42.6    52.0    60.0
?sum

height_vec <- c(180,169,173)
height_vec
## [1] 180 169 173
names(height_vec) <- c('Brian', 'Toby', 'Sherry')
height_vec
##  Brian   Toby Sherry 
##    180    169    173
name_vec <- c('Brian', 'Toby', 'Sherry')
names(height_vec) <- name_vec

height_vec
##  Brian   Toby Sherry 
##    180    169    173
height_vec > 175
##  Brian   Toby Sherry 
##   TRUE  FALSE  FALSE
height_vec[height_vec > 175]
## Brian 
##   180
height_vec[c(TRUE, FALSE, FALSE)]
## Brian 
##   180
height_vec[c(1)]
## Brian 
##   180

使用向量計算BMI

height_vec <- c(180, 169, 173)
weight_vec <- c(73, 87, 43)
names_vec  <- c('Brian', 'Toby', 'Sherry')

bmi_vec <- weight_vec / (height_vec / 100) ^ 2
names(bmi_vec) <- names_vec
bmi_vec
##    Brian     Toby   Sherry 
## 22.53086 30.46112 14.36734
bmi_vec[bmi_vec < 18.5 | bmi_vec >= 24]
##     Toby   Sherry 
## 30.46112 14.36734

Matrix

kevin <- c(85, 73)
marry <- c(72, 64)
jerry <- c(59, 66)
mat <- matrix(c(kevin, marry, jerry), nrow = 3, byrow = TRUE)

colnames(mat) <- c('first', 'second')
mat
##      first second
## [1,]    85     73
## [2,]    72     64
## [3,]    59     66
rownames(mat) <- c('kevin', 'marry', 'jerry')
mat
##       first second
## kevin    85     73
## marry    72     64
## jerry    59     66
mat2 <- matrix(c(kevin, marry, jerry), nrow = 3, byrow = TRUE, dimnames = list(c('kevin', 'marry', 'jerry'), c('first', 'second')))

mat2
##       first second
## kevin    85     73
## marry    72     64
## jerry    59     66
dim(mat2)
## [1] 3 2
nrow(mat2)
## [1] 3
ncol(mat2)
## [1] 2
mat2[1,]
##  first second 
##     85     73
mat2[,1]
## kevin marry jerry 
##    85    72    59
2:3
## [1] 2 3
mat2[2:3,]
##       first second
## marry    72     64
## jerry    59     66
mat2[2,1]
## [1] 72
mat2[2,1] <- 80
mat2[2,1]
## [1] 80
mat2
##       first second
## kevin    85     73
## marry    80     64
## jerry    59     66
mat3 <- rbind(mat2, c(78, 63))
rownames(mat3)[4] <- 'sam'
mat3
##       first second
## kevin    85     73
## marry    80     64
## jerry    59     66
## sam      78     63
mat4 <- cbind(mat2, c(82, 77, 70))
mat4
##       first second   
## kevin    85     73 82
## marry    80     64 77
## jerry    59     66 70
colnames(mat4)[3] <- 'third'
mat4
##       first second third
## kevin    85     73    82
## marry    80     64    77
## jerry    59     66    70
rowSums(mat2)
## kevin marry jerry 
##   158   144   125
colSums(mat2)
##  first second 
##    224    203
m1 <- matrix(1:4, byrow = TRUE, nrow = 2)
m2 <- matrix(5:8, byrow = TRUE, nrow = 2)
m1 + m2
##      [,1] [,2]
## [1,]    6    8
## [2,]   10   12
m1 - m2
##      [,1] [,2]
## [1,]   -4   -4
## [2,]   -4   -4
m1 * m2
##      [,1] [,2]
## [1,]    5   12
## [2,]   21   32
m1 / m2
##           [,1]      [,2]
## [1,] 0.2000000 0.3333333
## [2,] 0.4285714 0.5000000
mat <- matrix(c(kevin, marry, jerry), nrow = 3, byrow = TRUE, dimnames = list(c('kevin', 'marry', 'jerry'), c('first', 'second')))

mat[,'first'] * 0.4 + mat[, 'second'] * 0.6
## kevin marry jerry 
##  77.8  67.2  63.2

Factor

Weather <- c('sunny', 'rainy', 'cloudy', 'rainy', 'cloudy')
class(Weather)
## [1] "character"
weather_category <- factor(Weather)

weather_category
## [1] sunny  rainy  cloudy rainy  cloudy
## Levels: cloudy rainy sunny
levels(weather_category)
## [1] "cloudy" "rainy"  "sunny"

List

# List with name
Person <- list(names = "James", height = 180, employ = TRUE)
Person
## $names
## [1] "James"
## 
## $height
## [1] 180
## 
## $employ
## [1] TRUE
Person$names
## [1] "James"
Person$height
## [1] 180
Person$employ
## [1] TRUE
Person[[1]]
## [1] "James"
# List without name
Person2 <- list(c(67,72,88), c(54,66,78,99))
Person2
## [[1]]
## [1] 67 72 88
## 
## [[2]]
## [1] 54 66 78 99
Person2[[1]]
## [1] 67 72 88
Person2[[2]]
## [1] 54 66 78 99
li <- list(c(98,82,66,54), c(83, 72,77))
li
## [[1]]
## [1] 98 82 66 54
## 
## [[2]]
## [1] 83 72 77
lapply(li, sum)
## [[1]]
## [1] 300
## 
## [[2]]
## [1] 232

Data Frame

days <- c('mon', 'tue', 'wed', 'thu', 'fri')
temp <- c(22.2, 21, 23, 24.3, 25)
rain <- c(TRUE, TRUE, FALSE, FALSE, TRUE)
matrix(c(days, temp, rain), nrow = 3, byrow = TRUE)
##      [,1]   [,2]   [,3]    [,4]    [,5]  
## [1,] "mon"  "tue"  "wed"   "thu"   "fri" 
## [2,] "22.2" "21"   "23"    "24.3"  "25"  
## [3,] "TRUE" "TRUE" "FALSE" "FALSE" "TRUE"
df <- data.frame(days, temp, rain)
df
##   days temp  rain
## 1  mon 22.2  TRUE
## 2  tue 21.0  TRUE
## 3  wed 23.0 FALSE
## 4  thu 24.3 FALSE
## 5  fri 25.0  TRUE
class(df)
## [1] "data.frame"
str(df)
## 'data.frame':    5 obs. of  3 variables:
##  $ days: Factor w/ 5 levels "fri","mon","thu",..: 2 4 5 3 1
##  $ temp: num  22.2 21 23 24.3 25
##  $ rain: logi  TRUE TRUE FALSE FALSE TRUE
summary(df)
##   days        temp         rain        
##  fri:1   Min.   :21.0   Mode :logical  
##  mon:1   1st Qu.:22.2   FALSE:2        
##  thu:1   Median :23.0   TRUE :3        
##  tue:1   Mean   :23.1   NA's :0        
##  wed:1   3rd Qu.:24.3                  
##          Max.   :25.0
data()
data(iris)
iris
##     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
## 1            5.1         3.5          1.4         0.2     setosa
## 2            4.9         3.0          1.4         0.2     setosa
## 3            4.7         3.2          1.3         0.2     setosa
## 4            4.6         3.1          1.5         0.2     setosa
## 5            5.0         3.6          1.4         0.2     setosa
## 6            5.4         3.9          1.7         0.4     setosa
## 7            4.6         3.4          1.4         0.3     setosa
## 8            5.0         3.4          1.5         0.2     setosa
## 9            4.4         2.9          1.4         0.2     setosa
## 10           4.9         3.1          1.5         0.1     setosa
## 11           5.4         3.7          1.5         0.2     setosa
## 12           4.8         3.4          1.6         0.2     setosa
## 13           4.8         3.0          1.4         0.1     setosa
## 14           4.3         3.0          1.1         0.1     setosa
## 15           5.8         4.0          1.2         0.2     setosa
## 16           5.7         4.4          1.5         0.4     setosa
## 17           5.4         3.9          1.3         0.4     setosa
## 18           5.1         3.5          1.4         0.3     setosa
## 19           5.7         3.8          1.7         0.3     setosa
## 20           5.1         3.8          1.5         0.3     setosa
## 21           5.4         3.4          1.7         0.2     setosa
## 22           5.1         3.7          1.5         0.4     setosa
## 23           4.6         3.6          1.0         0.2     setosa
## 24           5.1         3.3          1.7         0.5     setosa
## 25           4.8         3.4          1.9         0.2     setosa
## 26           5.0         3.0          1.6         0.2     setosa
## 27           5.0         3.4          1.6         0.4     setosa
## 28           5.2         3.5          1.5         0.2     setosa
## 29           5.2         3.4          1.4         0.2     setosa
## 30           4.7         3.2          1.6         0.2     setosa
## 31           4.8         3.1          1.6         0.2     setosa
## 32           5.4         3.4          1.5         0.4     setosa
## 33           5.2         4.1          1.5         0.1     setosa
## 34           5.5         4.2          1.4         0.2     setosa
## 35           4.9         3.1          1.5         0.2     setosa
## 36           5.0         3.2          1.2         0.2     setosa
## 37           5.5         3.5          1.3         0.2     setosa
## 38           4.9         3.6          1.4         0.1     setosa
## 39           4.4         3.0          1.3         0.2     setosa
## 40           5.1         3.4          1.5         0.2     setosa
## 41           5.0         3.5          1.3         0.3     setosa
## 42           4.5         2.3          1.3         0.3     setosa
## 43           4.4         3.2          1.3         0.2     setosa
## 44           5.0         3.5          1.6         0.6     setosa
## 45           5.1         3.8          1.9         0.4     setosa
## 46           4.8         3.0          1.4         0.3     setosa
## 47           5.1         3.8          1.6         0.2     setosa
## 48           4.6         3.2          1.4         0.2     setosa
## 49           5.3         3.7          1.5         0.2     setosa
## 50           5.0         3.3          1.4         0.2     setosa
## 51           7.0         3.2          4.7         1.4 versicolor
## 52           6.4         3.2          4.5         1.5 versicolor
## 53           6.9         3.1          4.9         1.5 versicolor
## 54           5.5         2.3          4.0         1.3 versicolor
## 55           6.5         2.8          4.6         1.5 versicolor
## 56           5.7         2.8          4.5         1.3 versicolor
## 57           6.3         3.3          4.7         1.6 versicolor
## 58           4.9         2.4          3.3         1.0 versicolor
## 59           6.6         2.9          4.6         1.3 versicolor
## 60           5.2         2.7          3.9         1.4 versicolor
## 61           5.0         2.0          3.5         1.0 versicolor
## 62           5.9         3.0          4.2         1.5 versicolor
## 63           6.0         2.2          4.0         1.0 versicolor
## 64           6.1         2.9          4.7         1.4 versicolor
## 65           5.6         2.9          3.6         1.3 versicolor
## 66           6.7         3.1          4.4         1.4 versicolor
## 67           5.6         3.0          4.5         1.5 versicolor
## 68           5.8         2.7          4.1         1.0 versicolor
## 69           6.2         2.2          4.5         1.5 versicolor
## 70           5.6         2.5          3.9         1.1 versicolor
## 71           5.9         3.2          4.8         1.8 versicolor
## 72           6.1         2.8          4.0         1.3 versicolor
## 73           6.3         2.5          4.9         1.5 versicolor
## 74           6.1         2.8          4.7         1.2 versicolor
## 75           6.4         2.9          4.3         1.3 versicolor
## 76           6.6         3.0          4.4         1.4 versicolor
## 77           6.8         2.8          4.8         1.4 versicolor
## 78           6.7         3.0          5.0         1.7 versicolor
## 79           6.0         2.9          4.5         1.5 versicolor
## 80           5.7         2.6          3.5         1.0 versicolor
## 81           5.5         2.4          3.8         1.1 versicolor
## 82           5.5         2.4          3.7         1.0 versicolor
## 83           5.8         2.7          3.9         1.2 versicolor
## 84           6.0         2.7          5.1         1.6 versicolor
## 85           5.4         3.0          4.5         1.5 versicolor
## 86           6.0         3.4          4.5         1.6 versicolor
## 87           6.7         3.1          4.7         1.5 versicolor
## 88           6.3         2.3          4.4         1.3 versicolor
## 89           5.6         3.0          4.1         1.3 versicolor
## 90           5.5         2.5          4.0         1.3 versicolor
## 91           5.5         2.6          4.4         1.2 versicolor
## 92           6.1         3.0          4.6         1.4 versicolor
## 93           5.8         2.6          4.0         1.2 versicolor
## 94           5.0         2.3          3.3         1.0 versicolor
## 95           5.6         2.7          4.2         1.3 versicolor
## 96           5.7         3.0          4.2         1.2 versicolor
## 97           5.7         2.9          4.2         1.3 versicolor
## 98           6.2         2.9          4.3         1.3 versicolor
## 99           5.1         2.5          3.0         1.1 versicolor
## 100          5.7         2.8          4.1         1.3 versicolor
## 101          6.3         3.3          6.0         2.5  virginica
## 102          5.8         2.7          5.1         1.9  virginica
## 103          7.1         3.0          5.9         2.1  virginica
## 104          6.3         2.9          5.6         1.8  virginica
## 105          6.5         3.0          5.8         2.2  virginica
## 106          7.6         3.0          6.6         2.1  virginica
## 107          4.9         2.5          4.5         1.7  virginica
## 108          7.3         2.9          6.3         1.8  virginica
## 109          6.7         2.5          5.8         1.8  virginica
## 110          7.2         3.6          6.1         2.5  virginica
## 111          6.5         3.2          5.1         2.0  virginica
## 112          6.4         2.7          5.3         1.9  virginica
## 113          6.8         3.0          5.5         2.1  virginica
## 114          5.7         2.5          5.0         2.0  virginica
## 115          5.8         2.8          5.1         2.4  virginica
## 116          6.4         3.2          5.3         2.3  virginica
## 117          6.5         3.0          5.5         1.8  virginica
## 118          7.7         3.8          6.7         2.2  virginica
## 119          7.7         2.6          6.9         2.3  virginica
## 120          6.0         2.2          5.0         1.5  virginica
## 121          6.9         3.2          5.7         2.3  virginica
## 122          5.6         2.8          4.9         2.0  virginica
## 123          7.7         2.8          6.7         2.0  virginica
## 124          6.3         2.7          4.9         1.8  virginica
## 125          6.7         3.3          5.7         2.1  virginica
## 126          7.2         3.2          6.0         1.8  virginica
## 127          6.2         2.8          4.8         1.8  virginica
## 128          6.1         3.0          4.9         1.8  virginica
## 129          6.4         2.8          5.6         2.1  virginica
## 130          7.2         3.0          5.8         1.6  virginica
## 131          7.4         2.8          6.1         1.9  virginica
## 132          7.9         3.8          6.4         2.0  virginica
## 133          6.4         2.8          5.6         2.2  virginica
## 134          6.3         2.8          5.1         1.5  virginica
## 135          6.1         2.6          5.6         1.4  virginica
## 136          7.7         3.0          6.1         2.3  virginica
## 137          6.3         3.4          5.6         2.4  virginica
## 138          6.4         3.1          5.5         1.8  virginica
## 139          6.0         3.0          4.8         1.8  virginica
## 140          6.9         3.1          5.4         2.1  virginica
## 141          6.7         3.1          5.6         2.4  virginica
## 142          6.9         3.1          5.1         2.3  virginica
## 143          5.8         2.7          5.1         1.9  virginica
## 144          6.8         3.2          5.9         2.3  virginica
## 145          6.7         3.3          5.7         2.5  virginica
## 146          6.7         3.0          5.2         2.3  virginica
## 147          6.3         2.5          5.0         1.9  virginica
## 148          6.5         3.0          5.2         2.0  virginica
## 149          6.2         3.4          5.4         2.3  virginica
## 150          5.9         3.0          5.1         1.8  virginica
View(iris)
class(iris)
## [1] "data.frame"
head(iris)
##   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1          5.1         3.5          1.4         0.2  setosa
## 2          4.9         3.0          1.4         0.2  setosa
## 3          4.7         3.2          1.3         0.2  setosa
## 4          4.6         3.1          1.5         0.2  setosa
## 5          5.0         3.6          1.4         0.2  setosa
## 6          5.4         3.9          1.7         0.4  setosa
head(iris, 10)
##    Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1           5.1         3.5          1.4         0.2  setosa
## 2           4.9         3.0          1.4         0.2  setosa
## 3           4.7         3.2          1.3         0.2  setosa
## 4           4.6         3.1          1.5         0.2  setosa
## 5           5.0         3.6          1.4         0.2  setosa
## 6           5.4         3.9          1.7         0.4  setosa
## 7           4.6         3.4          1.4         0.3  setosa
## 8           5.0         3.4          1.5         0.2  setosa
## 9           4.4         2.9          1.4         0.2  setosa
## 10          4.9         3.1          1.5         0.1  setosa
?head

tail(iris)
##     Sepal.Length Sepal.Width Petal.Length Petal.Width   Species
## 145          6.7         3.3          5.7         2.5 virginica
## 146          6.7         3.0          5.2         2.3 virginica
## 147          6.3         2.5          5.0         1.9 virginica
## 148          6.5         3.0          5.2         2.0 virginica
## 149          6.2         3.4          5.4         2.3 virginica
## 150          5.9         3.0          5.1         1.8 virginica
tail(iris, 10)
##     Sepal.Length Sepal.Width Petal.Length Petal.Width   Species
## 141          6.7         3.1          5.6         2.4 virginica
## 142          6.9         3.1          5.1         2.3 virginica
## 143          5.8         2.7          5.1         1.9 virginica
## 144          6.8         3.2          5.9         2.3 virginica
## 145          6.7         3.3          5.7         2.5 virginica
## 146          6.7         3.0          5.2         2.3 virginica
## 147          6.3         2.5          5.0         1.9 virginica
## 148          6.5         3.0          5.2         2.0 virginica
## 149          6.2         3.4          5.4         2.3 virginica
## 150          5.9         3.0          5.1         1.8 virginica
iris[ 1:3 , ]
##   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1          5.1         3.5          1.4         0.2  setosa
## 2          4.9         3.0          1.4         0.2  setosa
## 3          4.7         3.2          1.3         0.2  setosa
iris[, 1]
##   [1] 5.1 4.9 4.7 4.6 5.0 5.4 4.6 5.0 4.4 4.9 5.4 4.8 4.8 4.3 5.8 5.7 5.4
##  [18] 5.1 5.7 5.1 5.4 5.1 4.6 5.1 4.8 5.0 5.0 5.2 5.2 4.7 4.8 5.4 5.2 5.5
##  [35] 4.9 5.0 5.5 4.9 4.4 5.1 5.0 4.5 4.4 5.0 5.1 4.8 5.1 4.6 5.3 5.0 7.0
##  [52] 6.4 6.9 5.5 6.5 5.7 6.3 4.9 6.6 5.2 5.0 5.9 6.0 6.1 5.6 6.7 5.6 5.8
##  [69] 6.2 5.6 5.9 6.1 6.3 6.1 6.4 6.6 6.8 6.7 6.0 5.7 5.5 5.5 5.8 6.0 5.4
##  [86] 6.0 6.7 6.3 5.6 5.5 5.5 6.1 5.8 5.0 5.6 5.7 5.7 6.2 5.1 5.7 6.3 5.8
## [103] 7.1 6.3 6.5 7.6 4.9 7.3 6.7 7.2 6.5 6.4 6.8 5.7 5.8 6.4 6.5 7.7 7.7
## [120] 6.0 6.9 5.6 7.7 6.3 6.7 7.2 6.2 6.1 6.4 7.2 7.4 7.9 6.4 6.3 6.1 7.7
## [137] 6.3 6.4 6.0 6.9 6.7 6.9 5.8 6.8 6.7 6.7 6.3 6.5 6.2 5.9
iris[1:3, 'Sepal.Length']
## [1] 5.1 4.9 4.7
iris[1:3, c('Sepal.Length', 'Sepal.Width')]
##   Sepal.Length Sepal.Width
## 1          5.1         3.5
## 2          4.9         3.0
## 3          4.7         3.2
iris$Sepal.Length
##   [1] 5.1 4.9 4.7 4.6 5.0 5.4 4.6 5.0 4.4 4.9 5.4 4.8 4.8 4.3 5.8 5.7 5.4
##  [18] 5.1 5.7 5.1 5.4 5.1 4.6 5.1 4.8 5.0 5.0 5.2 5.2 4.7 4.8 5.4 5.2 5.5
##  [35] 4.9 5.0 5.5 4.9 4.4 5.1 5.0 4.5 4.4 5.0 5.1 4.8 5.1 4.6 5.3 5.0 7.0
##  [52] 6.4 6.9 5.5 6.5 5.7 6.3 4.9 6.6 5.2 5.0 5.9 6.0 6.1 5.6 6.7 5.6 5.8
##  [69] 6.2 5.6 5.9 6.1 6.3 6.1 6.4 6.6 6.8 6.7 6.0 5.7 5.5 5.5 5.8 6.0 5.4
##  [86] 6.0 6.7 6.3 5.6 5.5 5.5 6.1 5.8 5.0 5.6 5.7 5.7 6.2 5.1 5.7 6.3 5.8
## [103] 7.1 6.3 6.5 7.6 4.9 7.3 6.7 7.2 6.5 6.4 6.8 5.7 5.8 6.4 6.5 7.7 7.7
## [120] 6.0 6.9 5.6 7.7 6.3 6.7 7.2 6.2 6.1 6.4 7.2 7.4 7.9 6.4 6.3 6.1 7.7
## [137] 6.3 6.4 6.0 6.9 6.7 6.9 5.8 6.8 6.7 6.7 6.3 6.5 6.2 5.9
iris[ iris$Sepal.Length >= 5 ,  ]
##     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
## 1            5.1         3.5          1.4         0.2     setosa
## 5            5.0         3.6          1.4         0.2     setosa
## 6            5.4         3.9          1.7         0.4     setosa
## 8            5.0         3.4          1.5         0.2     setosa
## 11           5.4         3.7          1.5         0.2     setosa
## 15           5.8         4.0          1.2         0.2     setosa
## 16           5.7         4.4          1.5         0.4     setosa
## 17           5.4         3.9          1.3         0.4     setosa
## 18           5.1         3.5          1.4         0.3     setosa
## 19           5.7         3.8          1.7         0.3     setosa
## 20           5.1         3.8          1.5         0.3     setosa
## 21           5.4         3.4          1.7         0.2     setosa
## 22           5.1         3.7          1.5         0.4     setosa
## 24           5.1         3.3          1.7         0.5     setosa
## 26           5.0         3.0          1.6         0.2     setosa
## 27           5.0         3.4          1.6         0.4     setosa
## 28           5.2         3.5          1.5         0.2     setosa
## 29           5.2         3.4          1.4         0.2     setosa
## 32           5.4         3.4          1.5         0.4     setosa
## 33           5.2         4.1          1.5         0.1     setosa
## 34           5.5         4.2          1.4         0.2     setosa
## 36           5.0         3.2          1.2         0.2     setosa
## 37           5.5         3.5          1.3         0.2     setosa
## 40           5.1         3.4          1.5         0.2     setosa
## 41           5.0         3.5          1.3         0.3     setosa
## 44           5.0         3.5          1.6         0.6     setosa
## 45           5.1         3.8          1.9         0.4     setosa
## 47           5.1         3.8          1.6         0.2     setosa
## 49           5.3         3.7          1.5         0.2     setosa
## 50           5.0         3.3          1.4         0.2     setosa
## 51           7.0         3.2          4.7         1.4 versicolor
## 52           6.4         3.2          4.5         1.5 versicolor
## 53           6.9         3.1          4.9         1.5 versicolor
## 54           5.5         2.3          4.0         1.3 versicolor
## 55           6.5         2.8          4.6         1.5 versicolor
## 56           5.7         2.8          4.5         1.3 versicolor
## 57           6.3         3.3          4.7         1.6 versicolor
## 59           6.6         2.9          4.6         1.3 versicolor
## 60           5.2         2.7          3.9         1.4 versicolor
## 61           5.0         2.0          3.5         1.0 versicolor
## 62           5.9         3.0          4.2         1.5 versicolor
## 63           6.0         2.2          4.0         1.0 versicolor
## 64           6.1         2.9          4.7         1.4 versicolor
## 65           5.6         2.9          3.6         1.3 versicolor
## 66           6.7         3.1          4.4         1.4 versicolor
## 67           5.6         3.0          4.5         1.5 versicolor
## 68           5.8         2.7          4.1         1.0 versicolor
## 69           6.2         2.2          4.5         1.5 versicolor
## 70           5.6         2.5          3.9         1.1 versicolor
## 71           5.9         3.2          4.8         1.8 versicolor
## 72           6.1         2.8          4.0         1.3 versicolor
## 73           6.3         2.5          4.9         1.5 versicolor
## 74           6.1         2.8          4.7         1.2 versicolor
## 75           6.4         2.9          4.3         1.3 versicolor
## 76           6.6         3.0          4.4         1.4 versicolor
## 77           6.8         2.8          4.8         1.4 versicolor
## 78           6.7         3.0          5.0         1.7 versicolor
## 79           6.0         2.9          4.5         1.5 versicolor
## 80           5.7         2.6          3.5         1.0 versicolor
## 81           5.5         2.4          3.8         1.1 versicolor
## 82           5.5         2.4          3.7         1.0 versicolor
## 83           5.8         2.7          3.9         1.2 versicolor
## 84           6.0         2.7          5.1         1.6 versicolor
## 85           5.4         3.0          4.5         1.5 versicolor
## 86           6.0         3.4          4.5         1.6 versicolor
## 87           6.7         3.1          4.7         1.5 versicolor
## 88           6.3         2.3          4.4         1.3 versicolor
## 89           5.6         3.0          4.1         1.3 versicolor
## 90           5.5         2.5          4.0         1.3 versicolor
## 91           5.5         2.6          4.4         1.2 versicolor
## 92           6.1         3.0          4.6         1.4 versicolor
## 93           5.8         2.6          4.0         1.2 versicolor
## 94           5.0         2.3          3.3         1.0 versicolor
## 95           5.6         2.7          4.2         1.3 versicolor
## 96           5.7         3.0          4.2         1.2 versicolor
## 97           5.7         2.9          4.2         1.3 versicolor
## 98           6.2         2.9          4.3         1.3 versicolor
## 99           5.1         2.5          3.0         1.1 versicolor
## 100          5.7         2.8          4.1         1.3 versicolor
## 101          6.3         3.3          6.0         2.5  virginica
## 102          5.8         2.7          5.1         1.9  virginica
## 103          7.1         3.0          5.9         2.1  virginica
## 104          6.3         2.9          5.6         1.8  virginica
## 105          6.5         3.0          5.8         2.2  virginica
## 106          7.6         3.0          6.6         2.1  virginica
## 108          7.3         2.9          6.3         1.8  virginica
## 109          6.7         2.5          5.8         1.8  virginica
## 110          7.2         3.6          6.1         2.5  virginica
## 111          6.5         3.2          5.1         2.0  virginica
## 112          6.4         2.7          5.3         1.9  virginica
## 113          6.8         3.0          5.5         2.1  virginica
## 114          5.7         2.5          5.0         2.0  virginica
## 115          5.8         2.8          5.1         2.4  virginica
## 116          6.4         3.2          5.3         2.3  virginica
## 117          6.5         3.0          5.5         1.8  virginica
## 118          7.7         3.8          6.7         2.2  virginica
## 119          7.7         2.6          6.9         2.3  virginica
## 120          6.0         2.2          5.0         1.5  virginica
## 121          6.9         3.2          5.7         2.3  virginica
## 122          5.6         2.8          4.9         2.0  virginica
## 123          7.7         2.8          6.7         2.0  virginica
## 124          6.3         2.7          4.9         1.8  virginica
## 125          6.7         3.3          5.7         2.1  virginica
## 126          7.2         3.2          6.0         1.8  virginica
## 127          6.2         2.8          4.8         1.8  virginica
## 128          6.1         3.0          4.9         1.8  virginica
## 129          6.4         2.8          5.6         2.1  virginica
## 130          7.2         3.0          5.8         1.6  virginica
## 131          7.4         2.8          6.1         1.9  virginica
## 132          7.9         3.8          6.4         2.0  virginica
## 133          6.4         2.8          5.6         2.2  virginica
## 134          6.3         2.8          5.1         1.5  virginica
## 135          6.1         2.6          5.6         1.4  virginica
## 136          7.7         3.0          6.1         2.3  virginica
## 137          6.3         3.4          5.6         2.4  virginica
## 138          6.4         3.1          5.5         1.8  virginica
## 139          6.0         3.0          4.8         1.8  virginica
## 140          6.9         3.1          5.4         2.1  virginica
## 141          6.7         3.1          5.6         2.4  virginica
## 142          6.9         3.1          5.1         2.3  virginica
## 143          5.8         2.7          5.1         1.9  virginica
## 144          6.8         3.2          5.9         2.3  virginica
## 145          6.7         3.3          5.7         2.5  virginica
## 146          6.7         3.0          5.2         2.3  virginica
## 147          6.3         2.5          5.0         1.9  virginica
## 148          6.5         3.0          5.2         2.0  virginica
## 149          6.2         3.4          5.4         2.3  virginica
## 150          5.9         3.0          5.1         1.8  virginica
which(iris$Sepal.Length >= 5)
##   [1]   1   5   6   8  11  15  16  17  18  19  20  21  22  24  26  27  28
##  [18]  29  32  33  34  36  37  40  41  44  45  47  49  50  51  52  53  54
##  [35]  55  56  57  59  60  61  62  63  64  65  66  67  68  69  70  71  72
##  [52]  73  74  75  76  77  78  79  80  81  82  83  84  85  86  87  88  89
##  [69]  90  91  92  93  94  95  96  97  98  99 100 101 102 103 104 105 106
##  [86] 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124
## [103] 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141
## [120] 142 143 144 145 146 147 148 149 150
iris[ which(iris$Sepal.Length >= 5) ,  ]
##     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
## 1            5.1         3.5          1.4         0.2     setosa
## 5            5.0         3.6          1.4         0.2     setosa
## 6            5.4         3.9          1.7         0.4     setosa
## 8            5.0         3.4          1.5         0.2     setosa
## 11           5.4         3.7          1.5         0.2     setosa
## 15           5.8         4.0          1.2         0.2     setosa
## 16           5.7         4.4          1.5         0.4     setosa
## 17           5.4         3.9          1.3         0.4     setosa
## 18           5.1         3.5          1.4         0.3     setosa
## 19           5.7         3.8          1.7         0.3     setosa
## 20           5.1         3.8          1.5         0.3     setosa
## 21           5.4         3.4          1.7         0.2     setosa
## 22           5.1         3.7          1.5         0.4     setosa
## 24           5.1         3.3          1.7         0.5     setosa
## 26           5.0         3.0          1.6         0.2     setosa
## 27           5.0         3.4          1.6         0.4     setosa
## 28           5.2         3.5          1.5         0.2     setosa
## 29           5.2         3.4          1.4         0.2     setosa
## 32           5.4         3.4          1.5         0.4     setosa
## 33           5.2         4.1          1.5         0.1     setosa
## 34           5.5         4.2          1.4         0.2     setosa
## 36           5.0         3.2          1.2         0.2     setosa
## 37           5.5         3.5          1.3         0.2     setosa
## 40           5.1         3.4          1.5         0.2     setosa
## 41           5.0         3.5          1.3         0.3     setosa
## 44           5.0         3.5          1.6         0.6     setosa
## 45           5.1         3.8          1.9         0.4     setosa
## 47           5.1         3.8          1.6         0.2     setosa
## 49           5.3         3.7          1.5         0.2     setosa
## 50           5.0         3.3          1.4         0.2     setosa
## 51           7.0         3.2          4.7         1.4 versicolor
## 52           6.4         3.2          4.5         1.5 versicolor
## 53           6.9         3.1          4.9         1.5 versicolor
## 54           5.5         2.3          4.0         1.3 versicolor
## 55           6.5         2.8          4.6         1.5 versicolor
## 56           5.7         2.8          4.5         1.3 versicolor
## 57           6.3         3.3          4.7         1.6 versicolor
## 59           6.6         2.9          4.6         1.3 versicolor
## 60           5.2         2.7          3.9         1.4 versicolor
## 61           5.0         2.0          3.5         1.0 versicolor
## 62           5.9         3.0          4.2         1.5 versicolor
## 63           6.0         2.2          4.0         1.0 versicolor
## 64           6.1         2.9          4.7         1.4 versicolor
## 65           5.6         2.9          3.6         1.3 versicolor
## 66           6.7         3.1          4.4         1.4 versicolor
## 67           5.6         3.0          4.5         1.5 versicolor
## 68           5.8         2.7          4.1         1.0 versicolor
## 69           6.2         2.2          4.5         1.5 versicolor
## 70           5.6         2.5          3.9         1.1 versicolor
## 71           5.9         3.2          4.8         1.8 versicolor
## 72           6.1         2.8          4.0         1.3 versicolor
## 73           6.3         2.5          4.9         1.5 versicolor
## 74           6.1         2.8          4.7         1.2 versicolor
## 75           6.4         2.9          4.3         1.3 versicolor
## 76           6.6         3.0          4.4         1.4 versicolor
## 77           6.8         2.8          4.8         1.4 versicolor
## 78           6.7         3.0          5.0         1.7 versicolor
## 79           6.0         2.9          4.5         1.5 versicolor
## 80           5.7         2.6          3.5         1.0 versicolor
## 81           5.5         2.4          3.8         1.1 versicolor
## 82           5.5         2.4          3.7         1.0 versicolor
## 83           5.8         2.7          3.9         1.2 versicolor
## 84           6.0         2.7          5.1         1.6 versicolor
## 85           5.4         3.0          4.5         1.5 versicolor
## 86           6.0         3.4          4.5         1.6 versicolor
## 87           6.7         3.1          4.7         1.5 versicolor
## 88           6.3         2.3          4.4         1.3 versicolor
## 89           5.6         3.0          4.1         1.3 versicolor
## 90           5.5         2.5          4.0         1.3 versicolor
## 91           5.5         2.6          4.4         1.2 versicolor
## 92           6.1         3.0          4.6         1.4 versicolor
## 93           5.8         2.6          4.0         1.2 versicolor
## 94           5.0         2.3          3.3         1.0 versicolor
## 95           5.6         2.7          4.2         1.3 versicolor
## 96           5.7         3.0          4.2         1.2 versicolor
## 97           5.7         2.9          4.2         1.3 versicolor
## 98           6.2         2.9          4.3         1.3 versicolor
## 99           5.1         2.5          3.0         1.1 versicolor
## 100          5.7         2.8          4.1         1.3 versicolor
## 101          6.3         3.3          6.0         2.5  virginica
## 102          5.8         2.7          5.1         1.9  virginica
## 103          7.1         3.0          5.9         2.1  virginica
## 104          6.3         2.9          5.6         1.8  virginica
## 105          6.5         3.0          5.8         2.2  virginica
## 106          7.6         3.0          6.6         2.1  virginica
## 108          7.3         2.9          6.3         1.8  virginica
## 109          6.7         2.5          5.8         1.8  virginica
## 110          7.2         3.6          6.1         2.5  virginica
## 111          6.5         3.2          5.1         2.0  virginica
## 112          6.4         2.7          5.3         1.9  virginica
## 113          6.8         3.0          5.5         2.1  virginica
## 114          5.7         2.5          5.0         2.0  virginica
## 115          5.8         2.8          5.1         2.4  virginica
## 116          6.4         3.2          5.3         2.3  virginica
## 117          6.5         3.0          5.5         1.8  virginica
## 118          7.7         3.8          6.7         2.2  virginica
## 119          7.7         2.6          6.9         2.3  virginica
## 120          6.0         2.2          5.0         1.5  virginica
## 121          6.9         3.2          5.7         2.3  virginica
## 122          5.6         2.8          4.9         2.0  virginica
## 123          7.7         2.8          6.7         2.0  virginica
## 124          6.3         2.7          4.9         1.8  virginica
## 125          6.7         3.3          5.7         2.1  virginica
## 126          7.2         3.2          6.0         1.8  virginica
## 127          6.2         2.8          4.8         1.8  virginica
## 128          6.1         3.0          4.9         1.8  virginica
## 129          6.4         2.8          5.6         2.1  virginica
## 130          7.2         3.0          5.8         1.6  virginica
## 131          7.4         2.8          6.1         1.9  virginica
## 132          7.9         3.8          6.4         2.0  virginica
## 133          6.4         2.8          5.6         2.2  virginica
## 134          6.3         2.8          5.1         1.5  virginica
## 135          6.1         2.6          5.6         1.4  virginica
## 136          7.7         3.0          6.1         2.3  virginica
## 137          6.3         3.4          5.6         2.4  virginica
## 138          6.4         3.1          5.5         1.8  virginica
## 139          6.0         3.0          4.8         1.8  virginica
## 140          6.9         3.1          5.4         2.1  virginica
## 141          6.7         3.1          5.6         2.4  virginica
## 142          6.9         3.1          5.1         2.3  virginica
## 143          5.8         2.7          5.1         1.9  virginica
## 144          6.8         3.2          5.9         2.3  virginica
## 145          6.7         3.3          5.7         2.5  virginica
## 146          6.7         3.0          5.2         2.3  virginica
## 147          6.3         2.5          5.0         1.9  virginica
## 148          6.5         3.0          5.2         2.0  virginica
## 149          6.2         3.4          5.4         2.3  virginica
## 150          5.9         3.0          5.1         1.8  virginica
sort(iris$Sepal.Length, decreasing = TRUE)
##   [1] 7.9 7.7 7.7 7.7 7.7 7.6 7.4 7.3 7.2 7.2 7.2 7.1 7.0 6.9 6.9 6.9 6.9
##  [18] 6.8 6.8 6.8 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.6 6.6 6.5 6.5 6.5 6.5
##  [35] 6.5 6.4 6.4 6.4 6.4 6.4 6.4 6.4 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3 6.3
##  [52] 6.2 6.2 6.2 6.2 6.1 6.1 6.1 6.1 6.1 6.1 6.0 6.0 6.0 6.0 6.0 6.0 5.9
##  [69] 5.9 5.9 5.8 5.8 5.8 5.8 5.8 5.8 5.8 5.7 5.7 5.7 5.7 5.7 5.7 5.7 5.7
##  [86] 5.6 5.6 5.6 5.6 5.6 5.6 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.4 5.4 5.4 5.4
## [103] 5.4 5.4 5.3 5.2 5.2 5.2 5.2 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.0
## [120] 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 4.9 4.9 4.9 4.9 4.9 4.9 4.8 4.8
## [137] 4.8 4.8 4.8 4.7 4.7 4.6 4.6 4.6 4.6 4.5 4.4 4.4 4.4 4.3
students <- c(52,43,67,89,66)
sort(students)
## [1] 43 52 66 67 89
order(students)
## [1] 2 1 5 3 4
students[order(students)]
## [1] 43 52 66 67 89
iris[order(iris$Sepal.Length, decreasing = TRUE), ]
##     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
## 132          7.9         3.8          6.4         2.0  virginica
## 118          7.7         3.8          6.7         2.2  virginica
## 119          7.7         2.6          6.9         2.3  virginica
## 123          7.7         2.8          6.7         2.0  virginica
## 136          7.7         3.0          6.1         2.3  virginica
## 106          7.6         3.0          6.6         2.1  virginica
## 131          7.4         2.8          6.1         1.9  virginica
## 108          7.3         2.9          6.3         1.8  virginica
## 110          7.2         3.6          6.1         2.5  virginica
## 126          7.2         3.2          6.0         1.8  virginica
## 130          7.2         3.0          5.8         1.6  virginica
## 103          7.1         3.0          5.9         2.1  virginica
## 51           7.0         3.2          4.7         1.4 versicolor
## 53           6.9         3.1          4.9         1.5 versicolor
## 121          6.9         3.2          5.7         2.3  virginica
## 140          6.9         3.1          5.4         2.1  virginica
## 142          6.9         3.1          5.1         2.3  virginica
## 77           6.8         2.8          4.8         1.4 versicolor
## 113          6.8         3.0          5.5         2.1  virginica
## 144          6.8         3.2          5.9         2.3  virginica
## 66           6.7         3.1          4.4         1.4 versicolor
## 78           6.7         3.0          5.0         1.7 versicolor
## 87           6.7         3.1          4.7         1.5 versicolor
## 109          6.7         2.5          5.8         1.8  virginica
## 125          6.7         3.3          5.7         2.1  virginica
## 141          6.7         3.1          5.6         2.4  virginica
## 145          6.7         3.3          5.7         2.5  virginica
## 146          6.7         3.0          5.2         2.3  virginica
## 59           6.6         2.9          4.6         1.3 versicolor
## 76           6.6         3.0          4.4         1.4 versicolor
## 55           6.5         2.8          4.6         1.5 versicolor
## 105          6.5         3.0          5.8         2.2  virginica
## 111          6.5         3.2          5.1         2.0  virginica
## 117          6.5         3.0          5.5         1.8  virginica
## 148          6.5         3.0          5.2         2.0  virginica
## 52           6.4         3.2          4.5         1.5 versicolor
## 75           6.4         2.9          4.3         1.3 versicolor
## 112          6.4         2.7          5.3         1.9  virginica
## 116          6.4         3.2          5.3         2.3  virginica
## 129          6.4         2.8          5.6         2.1  virginica
## 133          6.4         2.8          5.6         2.2  virginica
## 138          6.4         3.1          5.5         1.8  virginica
## 57           6.3         3.3          4.7         1.6 versicolor
## 73           6.3         2.5          4.9         1.5 versicolor
## 88           6.3         2.3          4.4         1.3 versicolor
## 101          6.3         3.3          6.0         2.5  virginica
## 104          6.3         2.9          5.6         1.8  virginica
## 124          6.3         2.7          4.9         1.8  virginica
## 134          6.3         2.8          5.1         1.5  virginica
## 137          6.3         3.4          5.6         2.4  virginica
## 147          6.3         2.5          5.0         1.9  virginica
## 69           6.2         2.2          4.5         1.5 versicolor
## 98           6.2         2.9          4.3         1.3 versicolor
## 127          6.2         2.8          4.8         1.8  virginica
## 149          6.2         3.4          5.4         2.3  virginica
## 64           6.1         2.9          4.7         1.4 versicolor
## 72           6.1         2.8          4.0         1.3 versicolor
## 74           6.1         2.8          4.7         1.2 versicolor
## 92           6.1         3.0          4.6         1.4 versicolor
## 128          6.1         3.0          4.9         1.8  virginica
## 135          6.1         2.6          5.6         1.4  virginica
## 63           6.0         2.2          4.0         1.0 versicolor
## 79           6.0         2.9          4.5         1.5 versicolor
## 84           6.0         2.7          5.1         1.6 versicolor
## 86           6.0         3.4          4.5         1.6 versicolor
## 120          6.0         2.2          5.0         1.5  virginica
## 139          6.0         3.0          4.8         1.8  virginica
## 62           5.9         3.0          4.2         1.5 versicolor
## 71           5.9         3.2          4.8         1.8 versicolor
## 150          5.9         3.0          5.1         1.8  virginica
## 15           5.8         4.0          1.2         0.2     setosa
## 68           5.8         2.7          4.1         1.0 versicolor
## 83           5.8         2.7          3.9         1.2 versicolor
## 93           5.8         2.6          4.0         1.2 versicolor
## 102          5.8         2.7          5.1         1.9  virginica
## 115          5.8         2.8          5.1         2.4  virginica
## 143          5.8         2.7          5.1         1.9  virginica
## 16           5.7         4.4          1.5         0.4     setosa
## 19           5.7         3.8          1.7         0.3     setosa
## 56           5.7         2.8          4.5         1.3 versicolor
## 80           5.7         2.6          3.5         1.0 versicolor
## 96           5.7         3.0          4.2         1.2 versicolor
## 97           5.7         2.9          4.2         1.3 versicolor
## 100          5.7         2.8          4.1         1.3 versicolor
## 114          5.7         2.5          5.0         2.0  virginica
## 65           5.6         2.9          3.6         1.3 versicolor
## 67           5.6         3.0          4.5         1.5 versicolor
## 70           5.6         2.5          3.9         1.1 versicolor
## 89           5.6         3.0          4.1         1.3 versicolor
## 95           5.6         2.7          4.2         1.3 versicolor
## 122          5.6         2.8          4.9         2.0  virginica
## 34           5.5         4.2          1.4         0.2     setosa
## 37           5.5         3.5          1.3         0.2     setosa
## 54           5.5         2.3          4.0         1.3 versicolor
## 81           5.5         2.4          3.8         1.1 versicolor
## 82           5.5         2.4          3.7         1.0 versicolor
## 90           5.5         2.5          4.0         1.3 versicolor
## 91           5.5         2.6          4.4         1.2 versicolor
## 6            5.4         3.9          1.7         0.4     setosa
## 11           5.4         3.7          1.5         0.2     setosa
## 17           5.4         3.9          1.3         0.4     setosa
## 21           5.4         3.4          1.7         0.2     setosa
## 32           5.4         3.4          1.5         0.4     setosa
## 85           5.4         3.0          4.5         1.5 versicolor
## 49           5.3         3.7          1.5         0.2     setosa
## 28           5.2         3.5          1.5         0.2     setosa
## 29           5.2         3.4          1.4         0.2     setosa
## 33           5.2         4.1          1.5         0.1     setosa
## 60           5.2         2.7          3.9         1.4 versicolor
## 1            5.1         3.5          1.4         0.2     setosa
## 18           5.1         3.5          1.4         0.3     setosa
## 20           5.1         3.8          1.5         0.3     setosa
## 22           5.1         3.7          1.5         0.4     setosa
## 24           5.1         3.3          1.7         0.5     setosa
## 40           5.1         3.4          1.5         0.2     setosa
## 45           5.1         3.8          1.9         0.4     setosa
## 47           5.1         3.8          1.6         0.2     setosa
## 99           5.1         2.5          3.0         1.1 versicolor
## 5            5.0         3.6          1.4         0.2     setosa
## 8            5.0         3.4          1.5         0.2     setosa
## 26           5.0         3.0          1.6         0.2     setosa
## 27           5.0         3.4          1.6         0.4     setosa
## 36           5.0         3.2          1.2         0.2     setosa
## 41           5.0         3.5          1.3         0.3     setosa
## 44           5.0         3.5          1.6         0.6     setosa
## 50           5.0         3.3          1.4         0.2     setosa
## 61           5.0         2.0          3.5         1.0 versicolor
## 94           5.0         2.3          3.3         1.0 versicolor
## 2            4.9         3.0          1.4         0.2     setosa
## 10           4.9         3.1          1.5         0.1     setosa
## 35           4.9         3.1          1.5         0.2     setosa
## 38           4.9         3.6          1.4         0.1     setosa
## 58           4.9         2.4          3.3         1.0 versicolor
## 107          4.9         2.5          4.5         1.7  virginica
## 12           4.8         3.4          1.6         0.2     setosa
## 13           4.8         3.0          1.4         0.1     setosa
## 25           4.8         3.4          1.9         0.2     setosa
## 31           4.8         3.1          1.6         0.2     setosa
## 46           4.8         3.0          1.4         0.3     setosa
## 3            4.7         3.2          1.3         0.2     setosa
## 30           4.7         3.2          1.6         0.2     setosa
## 4            4.6         3.1          1.5         0.2     setosa
## 7            4.6         3.4          1.4         0.3     setosa
## 23           4.6         3.6          1.0         0.2     setosa
## 48           4.6         3.2          1.4         0.2     setosa
## 42           4.5         2.3          1.3         0.3     setosa
## 9            4.4         2.9          1.4         0.2     setosa
## 39           4.4         3.0          1.3         0.2     setosa
## 43           4.4         3.2          1.3         0.2     setosa
## 14           4.3         3.0          1.1         0.1     setosa

Data Analysis

getwd()
# setwd()
#download.file('https://raw.githubusercontent.com/ywchiu/cwgroup/master/data/lvr_prices_mac.csv', 'lvr_price.csv')



library(readr)
lvr_price <- read_csv("C:/Users/User/ipost/lvr_price.csv", col_types = cols(total_price = col_number()))

class(lvr_price)

daan <- lvr_price[lvr_price$area == '大安區', ]
sum(daan$total_price)
mean(daan$total_price)
summary(daan$total_price)



zhongshan <- lvr_price[lvr_price$area == '中山區', c('address', 'total_price')]
idx <- order(zhongshan$total_price, decreasing = TRUE)
res <- zhongshan[idx,]
res[1:3,]


addnum <- function(a,b){
  a + b
}
addnum(3,5)


addnum2 <- function(a,b = 2){
  a + b
}

addnum2(3)

getTopThree <- function(area){
  zhongshan <- lvr_price[lvr_price$area == area, c('address', 'total_price')]
  idx <- order(zhongshan$total_price, decreasing = TRUE)
  res <- zhongshan[idx,]
  res[1:3,]
}

getTopThree('大安區')


tapply(lvr_price$total_price, lvr_price$area, mean)

price_per_sec <- tapply(lvr_price$total_price, lvr_price$area, function(e)mean(e,na.rm=TRUE))

barplot(sort(price_per_sec, decreasing = TRUE), main= "各區平均價", xlab = "區域", ylab = "價格", col="blue")


boxplot(log(total_price) ~ area, data = lvr_price, main= "房價箱型圖", xlab = "區域", ylab = "價格(log)")


library(dplyr)
lvr_price %>% select(total_price, area) %>% filter(area == '大安區')

lvr_price$trading_ym <- as.Date(format(lvr_price$trading_ymd, '%Y-%m-01'))

lvr_stat <- lvr_price %>% select(trading_ym, area, total_price) %>% filter(trading_ym >= '2012-01-01') %>% group_by(trading_ym, area) %>% summarise(overall_price = sum(total_price))

plot(overall_price ~ trading_ym , lvr_stat[lvr_stat$area == '大安區', ], type = 'l')

lvr_stat$area <- as.factor(lvr_stat$area)

par(mfrow = c(3,4))
for(a in levels(lvr_stat$area)){
  plot(overall_price ~ trading_ym , lvr_stat[lvr_stat$area == a, ], type = 'l', main = a)
}

library(tidyr)
price_pivot <- spread(lvr_stat, trading_ym, overall_price, fill=0)
View(price_pivot)