qoiqpwqr 发表于 2013-7-20 11:32
> a a
A B C D
Min. 26.56 26.02 25.49 26.54
列数据量不同时,该方法行不通
> a <- apply(data, 2, summary)
> a
$A
Min. 1st Qu. Median Mean 3rd Qu. Max.
26.56 27.70 29.17 29.19 29.62 43.15
$B
Min. 1st Qu. Median Mean 3rd Qu. Max. NA's
26.02 29.22 29.34 29.23 29.60 30.55 3
$C
Min. 1st Qu. Median Mean 3rd Qu. Max.
25.49 28.25 29.15 29.11 29.78 35.13
$D
Min. 1st Qu. Median Mean 3rd Qu. Max. NA's
26.54 28.35 29.52 29.70 30.28 40.06 3
> a[2,1]
Error in a[2, 1] : incorrect number of dimensions