Loading Data
library("dslabs")
data("murders")
df <- murders
Q1: Q:1 Use the function c to create a vector with the average high
temperatures in January for Beijing, Lagos,Paris, Rio de Janeiro, San
Juan and Toronto, which are 35, 88, 42, 84, 81, and 30 degrees
Fahrenheit.Call the object temp.
temp<-c('Beijing'=35,'Lagos'=88,'Paris'=42,' Rio de Janeiro'=84, 'San Juan'=81, 'Toronto'=30)
temp
## Beijing Lagos Paris Rio de Janeiro San Juan
## 35 88 42 84 81
## Toronto
## 30
Q2: Now create a vector with the city names and call the object
city.
city<-c( 'Beijing', 'Lagos','Paris', 'Rio de Janeiro', 'San Juan', 'Toronto')
city
## [1] "Beijing" "Lagos" "Paris" "Rio de Janeiro"
## [5] "San Juan" "Toronto"
Q3: Use the names function and the objects defined in the previous
exercises to associate the temperature data with its corresponding
city.
city<-c( 'Beijing', 'Lagos','Paris', 'Rio de Janeiro', 'San Juan', 'Toronto')
temp<-c(35, 88, 42, 84, 81,30 )
names(temp)<-city
temp
## Beijing Lagos Paris Rio de Janeiro San Juan
## 35 88 42 84 81
## Toronto
## 30
Q4: Use the [ and : operators to access the temperature of the first
three cities on the list.
city[1:3]
## [1] "Beijing" "Lagos" "Paris"
Q5: Use the [ operator to access the temperature of Paris and San
Juan.
temp['Paris']
## Paris
## 42
temp['San Juan']
## San Juan
## 81
Q6: Use the : operator to create a sequence of numbers 12, 13, 14,…,
73
seq(12,73)
## [1] 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
## [26] 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
## [51] 62 63 64 65 66 67 68 69 70 71 72 73
Q7: Create a vector containing all the positive odd numbers smaller
than 100.
positive_odd_num<-seq(1,100,2)
positive_odd_num
## [1] 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
## [26] 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99
Q8: Create a vector of numbers that starts at 6, does not pass 55,
and adds numbers in increments of 4/7:6, 6+4/7, 6+8/7, etc.. How many
numbers does the list have? Hint: use seq and length.
my_sequence <- seq(from = 6, by = 4/7, to = 55)
my_sequence
## [1] 6.000000 6.571429 7.142857 7.714286 8.285714 8.857143 9.428571
## [8] 10.000000 10.571429 11.142857 11.714286 12.285714 12.857143 13.428571
## [15] 14.000000 14.571429 15.142857 15.714286 16.285714 16.857143 17.428571
## [22] 18.000000 18.571429 19.142857 19.714286 20.285714 20.857143 21.428571
## [29] 22.000000 22.571429 23.142857 23.714286 24.285714 24.857143 25.428571
## [36] 26.000000 26.571429 27.142857 27.714286 28.285714 28.857143 29.428571
## [43] 30.000000 30.571429 31.142857 31.714286 32.285714 32.857143 33.428571
## [50] 34.000000 34.571429 35.142857 35.714286 36.285714 36.857143 37.428571
## [57] 38.000000 38.571429 39.142857 39.714286 40.285714 40.857143 41.428571
## [64] 42.000000 42.571429 43.142857 43.714286 44.285714 44.857143 45.428571
## [71] 46.000000 46.571429 47.142857 47.714286 48.285714 48.857143 49.428571
## [78] 50.000000 50.571429 51.142857 51.714286 52.285714 52.857143 53.428571
## [85] 54.000000 54.571429
length(my_sequence)
## [1] 86
Q9: What is the class of the following object a <- seq(1, 10,
0.5)?
a <- seq(1, 10, 0.5)
class(a)
## [1] "numeric"
Q10: What is the class of the following object a <- seq(1,
10)?
a <- seq(1, 10)
class(a)
## [1] "integer"
Q12: Defne the following vector:x <- c(“1”, “3”, “5”) and coerce
it to get integers
x <- c("1", "3", "5")
x<-as.integer(x)
x
## [1] 1 3 5