r - Subset data frame using row names

Question

I have a data frame like this:

       x1    x2    x3
271    3     5      2
553    2     4      1
563    2     5      3

When I try to select a row based on the row name, e.g. 271, it errors:

df[271, ]
# Error in xj[i, , drop = FALSE] : subscript out of bounds

How can I select these rows based on the row names (e.g. 271, 553, 563)?

Answer 1

You need to reference the rownames of your data.frame:

dfsub[rownames(dfsub) == 271,] #where dfsub is your subsetted data.frame

EDIT:

as @koekenbakker commented, there is a shorthand to reference the rownames by using ''. So this would be:

dfsub['271',] #where dfsub is your subsetted data.frame and 271 the rowname