How do I delete rows in a data frame?

r row

R newbie · Sep 8, 2012 · Viewed 1.3M times · Source

I have a data frame named "mydata" that looks like this this:

   A  B  C   D 
1. 5  4  4   4 
2. 5  4  4   4 
3. 5  4  4   4 
4. 5  4  4   4 
5. 5  4  4   4 
6. 5  4  4   4 
7. 5  4  4   4

I'd like to delete row 2,4,6. For example, like this:

   A  B  C   D
1. 5  4  4  4 
3. 5  4  4  4 
5. 5  4  4  4 
7. 5  4  4  4

Answer

The key idea is you form a set of the rows you want to remove, and keep the complement of that set.

In R, the complement of a set is given by the '-' operator.

So, assuming the data.frame is called myData:

myData[-c(2, 4, 6), ]   # notice the -

Of course, don't forget to "reassign" myData if you wanted to drop those rows entirely---otherwise, R just prints the results.

myData <- myData[-c(2, 4, 6), ]