The dplyr package contains many functions used to manipulate data. The first 10 observations of the mtcars dataset are displayed below.
library(dplyr)
mtcars %>% head(10)## # A tibble: 10 x 11
## mpg cyl disp hp drat wt qsec vs am gear carb
## <dbl> <fct> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <fct> <fct> <dbl>
## 1 21 6 160 110 3.9 2.62 16.5 0 Manual 4 4
## 2 21 6 160 110 3.9 2.88 17.0 0 Manual 4 4
## 3 22.8 4 108 93 3.85 2.32 18.6 1 Manual 4 1
## 4 21.4 6 258 110 3.08 3.22 19.4 1 Automatic 3 1
## 5 18.7 8 360 175 3.15 3.44 17.0 0 Automatic 3 2
## 6 18.1 6 225 105 2.76 3.46 20.2 1 Automatic 3 1
## 7 14.3 8 360 245 3.21 3.57 15.8 0 Automatic 3 4
## 8 24.4 4 147. 62 3.69 3.19 20 1 Automatic 4 2
## 9 22.8 4 141. 95 3.92 3.15 22.9 1 Automatic 4 2
## 10 19.2 6 168. 123 3.92 3.44 18.3 1 Automatic 4 4It is often desirable to sort a data set by a particular variable. For example, you may want to look for trends in cars based on mpg. The code below will sort the mtcars dataset by mpg and display the results in descending order.
mtcars %>% arrange(desc(mpg)) %>% head(10)## # A tibble: 10 x 11
## mpg cyl disp hp drat wt qsec vs am gear carb
## <dbl> <fct> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <fct> <fct> <dbl>
## 1 33.9 4 71.1 65 4.22 1.84 19.9 1 Manual 4 1
## 2 32.4 4 78.7 66 4.08 2.2 19.5 1 Manual 4 1
## 3 30.4 4 75.7 52 4.93 1.62 18.5 1 Manual 4 2
## 4 30.4 4 95.1 113 3.77 1.51 16.9 1 Manual 5 2
## 5 27.3 4 79 66 4.08 1.94 18.9 1 Manual 4 1
## 6 26 4 120. 91 4.43 2.14 16.7 0 Manual 5 2
## 7 24.4 4 147. 62 3.69 3.19 20 1 Automatic 4 2
## 8 22.8 4 108 93 3.85 2.32 18.6 1 Manual 4 1
## 9 22.8 4 141. 95 3.92 3.15 22.9 1 Automatic 4 2
## 10 21.5 4 120. 97 3.7 2.46 20.0 1 Automatic 3 1Mathematicss, Computer Science, and Statistics Department Gustavus Adolphus College