[R] apply and cor()
Micha Silver
tsvibar at gmail.com
Fri May 12 16:57:34 CEST 2017
I have two data.frames, one with a single row of 31 columns, and the
second with 269 rows and the same 31 columns.
> dim(compare_data)
[1] 269 31
> dim(test_data)
[1] 1 31
I want to apply cor() between the one row of 'test_data', and each row
of the 'compare_data' .
I tried 'apply' but I get this error:
> apply(compare_data, 1, function(r) {cor(compare_data[r,], test_data)})
Error in cor(compare_data[r, ], test_data) : incompatible dimensions
In order to try to understand I did:
> dims <- apply(compare_data, 1, function(r) {dim(compare_data[r,])})
> head(dims)
20 73 103 118 130 142 151 154 191 205 217 222 227 232 240 275 282
301 320 359 360 551 589 653 789 801 808 812
[1,] 9 8 8 9 5 9 8 11 6 15 12 13 10 7 9 14 8
11 9 11 11 12 9 14 5 8 9 10
[2,] 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31
31 31 31 31 31 31 31 31 31 31 31
840 856 857 867 885 970 983 985 1103 1107 1197 1207 1237 1262 1279
1282 1332 1357 1358 1392 1411 1435 1458 1473
[1,] 14 11 12 8 10 2 7 9 10 8 10 13 11 7 9
12 11 11 16 10 10 12 10 10
[2,] 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31
31 31 31 31 31 31 31 31 31
and indeed I am getting different row dimensions. I expected "1 31" for
each. What are the values 9,8,8,9,5... in the [1,] dimension?
If I test the compare_data data.frame one row at a time:
> dim(compare_data['20',])
[1] 1 31
> dim(compare_data['1473',])
[1] 1 31
It looks as I expected.
What am I missing??
Thanks
--
Micha Silver
cell: +972-523-665918
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