Victor Van Hee Victor Van Hee - 5 days ago 5
R Question

How to convert a table to a data frame

I have a table in R that has

str()
of this:

table [1:3, 1:4] 0.166 0.319 0.457 0.261 0.248 ...
- attr(*, "dimnames")=List of 2
..$ x: chr [1:3] "Metro >=1 million" "Metro <1 million" "Non-Metro Counties"
..$ y: chr [1:4] "q1" "q2" "q3" "q4"


And looks like this when I print it:

y
x q1 q2 q3 q4
Metro >=1 million 0.1663567 0.2612212 0.2670441 0.3053781
Metro <1 million 0.3192857 0.2480012 0.2341030 0.1986102
Non-Metro Counties 0.4570341 0.2044960 0.2121102 0.1263597


I want to get rid of the
x
and
y
and convert it to a data frame that looks exactly the same as the above (three rows, four columns), but without the
x
or
y
. If I use
as.data.frame(mytable)
, instead I get this:

x y Freq
1 Metro >=1 million q1 0.1663567
2 Metro <1 million q1 0.3192857
3 Non-Metro Counties q1 0.4570341
4 Metro >=1 million q2 0.2612212
5 Metro <1 million q2 0.2480012
6 Non-Metro Counties q2 0.2044960
7 Metro >=1 million q3 0.2670441
8 Metro <1 million q3 0.2341030
9 Non-Metro Counties q3 0.2121102
10 Metro >=1 million q4 0.3053781
11 Metro <1 million q4 0.1986102
12 Non-Metro Counties q4 0.1263597


I probably fundamentally do not understand how tables relate to data frames.

Answer

I figured it out already.

as.data.frame.matrix(mytable) 

does what I need -- apparently, the table needs to somehow be converted to a matrix in order to be appropriately translated into a data frame. I found more details on this as.data.frame.matrix() function for contingency tables at the Computational Ecology blog.

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