Filtering data

Data filtering is the most common requirement for users who want to analyze partial data of interest rather than the whole dataset. In database operations, we can use a SQL command with a where clause to subset the data. In R, we can simply use the square bracket to perform filtering.

Getting ready

Refer to the Converting data types recipe and convert each attribute of imported data into the proper data type. Also, rename the columns of the employees and salaries datasets by following the steps from the Renaming the data variable recipe.

How to do it…

Perform the following steps to filter data:

1. First, use head and tail to subset the first three rows and last three rows from the employees dataset:

   > head(employees, 3)
     emp_no birth_date first_name last_name gender  hire_date
   1  10001 1953-09-02     Georgi   Facello      M 1986-06-26
   2  10002 1964-06-02    Bezalel    Simmel      F 1985-11-21
   3  10003 1959-12-03      Parto   Bamford      M 1986-08-28
   
   > tail(employees, 3)
   ...