Selecting the bottom of a data frame
head(___, n = ___)
tail(___, n = ___)The tail() function can be used to select the bottom rows of a data frame. Similar to the head() function it also accepts a parameter n to specify the number rows to be returned.
For example, to select the last five rows from the TitanicSurvival dataset you can write:
Input
tail(TitanicSurvival, n = 5)
Output
survived sex age passengerClass Zabour, Miss. Hileni no female 14.5 3rd Zabour, Miss. Thamine no female NA 3rd Zakarian, Mr. Mapriededer no male 26.5 3rd Zakarian, Mr. Ortin no male 27.0 3rd Zimmerman, Mr. Leo no male 29.0 3rd
The head and tail functions can also be combined to select a fragment of the data set from the middle. To select the first five rows from the bottom 500 rows you can write:
Input
head(tail(TitanicSurvival, n = 500), n = 5)
Output
survived sex age passengerClass Ford, Mr. Edward Watson no male 18 3rd Ford, Mr. William Neal no male 16 3rd Ford, Mrs. Edward (Margaret Ann no female 48 3rd Fox, Mr. Patrick no male NA 3rd Franklin, Mr. Charles (Charles no male NA 3rd