Will Glass Will Glass - 3 days ago 5
R Question

How to get row from R data.frame

I have a data.frame with column headers.

How can I get a specific row from the data.frame as a list (with the column headers as keys for the list)?

Specifically, my data.frame is


A B C
1 5 4.25 4.5
2 3.5 4 2.5
3 3.25 4 4
4 4.25 4.5 2.25
5 1.5 4.5 3


And I want to get a row that's the equivalent of

> c(a=5, b=4.25, c=4.5)
a b c
5.0 4.25 4.5

Answer
x[r,]

where r is the row you're interested in. Try this, for example:

#Add your data
x <- structure(list(A = c(5,    3.5, 3.25, 4.25,  1.5 ), 
                    B = c(4.25, 4,   4,    4.5,   4.5 ),
                    C = c(4.5,  2.5, 4,    2.25,  3   )
               ),
               .Names    = c("A", "B", "C"),
               class     = "data.frame",
               row.names = c(NA, -5L)
     )

#The vector your result should match
y<-c(A=5, B=4.25, C=4.5)

#Test that the items in the row match the vector you wanted
x[1,]==y

This page (from this useful site) has good information on indexing like this.

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