如何从数据框中返回 2 个特定行？

Question

firstVector <- c("A", "B", "C", "D", "E")
secondVector <- c(1, 2, 3, 4, 5)
thirdVector <- c("a", "b", "c", "d", "e")


myDataFrame <- data.frame(firstVector, secondVector, thirdVector)

How do I extract row 3 and 4 from my data frame? I want to print it row 3 and 4 in order it to look like this:

    firstVector secondVector thirdVector
3     C            3            c
4     D            4            d

Answer 1

You can subset your dataframe like this [rows,columns]:

myDataFrame[c(3,4),]

In your case you want a vector containing rows 3 and 4, therefore c(3,4), you can add more columns in the vector to subset more rows, for example c(1,2,3,12). If you dont provide an argument it returns the whole dimension. In your example you subset rows, and return all the columns

it's the same for columns:

myDataFrame[c(3,4),c(1,2)]

you can subset rows 3 and 4 and columns 1 and 2.

Another way to do this is using : c(1:4) means from 1 to 4

Hope this helps