r - 如何删除数据框中的行？(How do I delete rows in a data frame?)

Question

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

(我有一个名为“ mydata”的数据框，看起来像这样：)

   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.

(我想删除第2、4、6行。)

For example, like this:

(例如，像这样：)

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

  ask by R newbie translate from so

Answer 1

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

(关键思想是形成要删除的行的集合，并保留该集合的补充。)

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

(在R中，集合的补码由'-'运算符给出。)

So, assuming the data.frame is called myData :

(因此，假设data.frame称为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.

(当然，如果您想完全删除那些行，请不要忘记“重新分配” myData否则，R只会打印结果。)

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