Selecting rows

To select rows from a dataframe use the filter() function (again from dplyr).

If we only wanted to rows for 6-cylindered cars, we could write:

filter(mtcars, cyl==6)
   mpg cyl  disp  hp drat    wt  qsec vs am gear carb
1 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
2 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
3 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
4 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
5 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
6 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
7 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6