代码及数据如下
> data<-read.csv("test.csv")
> data
A B C D
127.68 29.25 28.11 28.82
229.56 29.13 26.06 28.70
326.56 29.52 35.13 27.42
427.13 29.33 30.35 34.38
527.40 29.21 29.39 29.01
630.49 29.25 28.95 28.23
728.80 29.43 29.15 26.91
829.17 29.31 28.91 40.06
927.72 29.33 29.78 30.61
10 43.15 29.56 29.88 30.23
11 29.62 29.70 29.88 29.72
12 30.25 29.35 28.23 27.83
13 30.37 28.95 26.85 31.65
14 29.37 29.41 30.90 30.04
15 29.17 29.11 29.23 30.19
16 26.67 29.05 29.72 27.66
17 26.91 29.41 28.29 30.29
18 26.67 29.47 28.86 30.47
19 29.11 29.31 25.49 28.21
20 27.70 29.23 29.03 26.54
21 29.50 29.86 27.40 30.72
22 29.47 29.62 29.78 27.01
23 29.60 26.91 28.25 30.68
24 26.71 26.02 30.15 28.72
25 31.00 30.55 29.90 29.84
26 31.18 28.88 28.97 29.13
27 30.17 29.68 30.07 29.96
28 30.15 29.88 28.21 30.02
29 28.50 29.70 28.21 28.74
30 29.62 29.62 29.70 29.33
31 27.97 30.39 28.80 29.37
32 28.07 28.62 29.62 28.46
33 27.91 30.61 29.35 29.41
> a<-summary(data)
> a
A B C D
Min. :26.56 Min. :26.02 Min. :25.49 Min. :26.54
1st Qu.:27.70 1st Qu.:29.21 1st Qu.:28.25 1st Qu.:28.46
Median :29.17 Median :29.35 Median :29.15 Median :29.37
Mean :29.19 Mean :29.29 Mean :29.11 Mean :29.65
3rd Qu.:29.62 3rd Qu.:29.62 3rd Qu.:29.78 3rd Qu.:30.23
Max. :43.15 Max. :30.61 Max. :35.13 Max. :40.06
我想提取各列中的6个参数：Min. 、 1st Qu.，Median的数值，如何做呢？