[R] problem selecting rows meeting a criterion

Jim Bouldin jrbouldin at ucdavis.edu
Mon Aug 10 23:49:29 CEST 2009


When I try to select only those rows from the following data frame, called
"data", in which X > Y

   X Y       V3
2  2 1 8.062258
3  3 1 2.236068
4  4 1 6.324555
5  5 1 5.000000
6  1 2 8.062258
8  3 2 9.486833
9  4 2 2.236068
10 5 2 5.656854
11 1 3 2.236068
12 2 3 9.486833
14 4 3 8.062258
15 5 3 5.099020
16 1 4 6.324555
17 2 4 2.236068
18 3 4 8.062258
20 5 4 5.385165
21 1 5 5.000000
22 2 5 5.656854
23 3 5 5.099020
24 4 5 5.385165

using the commands
> attach(data) 
> data2 = data[X >Y,];data2

I get this for data2:

   X Y       V3
3  3 1 2.236068
4  4 1 6.324555
5  5 1 5.000000
6  1 2 8.062258
10 5 2 5.656854
11 1 3 2.236068
12 2 3 9.486833
17 2 4 2.236068
18 3 4 8.062258
24 4 5 5.385165

Clearly, this is not what I intend but I cannot figure out what I've done
wrong.  Any help appreciated.  Thanks.

Jim Bouldin




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