R 返回每行最小列的索引 [英] R return the index of the minimum column for each row

问题描述

我有一个包含 4 列的 data.frame(如下所示).我想找到每一行的最小列(不是值)的索引.有什么想法可以实现吗?

I have a data.frame that contains 4 columns (given below). I want to find the index of the minimum column (NOT THE VALUE) for each row. Any idea hiw to achieve that?

> d
            V1         V2         V3         V4
1  0.388116155 0.98999967 0.41548536 0.76093748
2  0.495971331 0.47173142 0.51582728 0.06789924
3  0.436495321 0.48699268 0.21187838 0.54139290
4  0.313514389 0.50265539 0.08054103 0.46019601
5  0.277275961 0.39055360 0.29594162 0.70622532
6  0.264804739 0.86996266 0.85708635 0.61136741
7  0.627344463 0.54277873 0.96769568 0.80399490
8  0.814420492 0.35362949 0.39023446 0.39246250
9  0.517459983 0.65895805 0.93662382 0.06762166
10 0.498319937 0.67081260 0.43225997 0.42139151
11 0.046862110 0.97304915 0.06542971 0.09779383
12 0.619009734 0.82363618 0.14514799 0.52858058
13 0.007262782 0.82203403 0.08573499 0.61094206
14 0.001602586 0.33241230 0.57762669 0.45285004
15 0.698388370 0.83541257 0.21051568 0.84431347
16 0.296088411 0.34363164 0.02179999 0.70551493
17 0.897869571 0.50625928 0.92861583 0.61249019
18 0.372497428 0.29025182 0.23201891 0.55737699
19 0.172931860 0.03604668 0.50291560 0.10850847
20 0.988827604 0.15800337 0.87999839 0.09899663

所以我想要以下输出:

1    1
2    4
3    3
4    3

对所有行继续.谢谢

推荐答案

你的英文描述表明你想要:

Your English description suggests you want:

 apply( df, 1, which.min)

但是您给出的答案未格式化为向量，如果上述解释正确，则不是正确答案.哦等等，你期待的是行号.

But the answer you give is not formatted as a vector and is not the correct answer if the above interpretation is correct. Oh wait, you were expecting rownumbers.

 as.matrix(apply( d, 1, which.min))

   [,1]
1     1
2     4
3     3
4     3
5     1
6     1
7     2
8     2
9     4
10    4
11    1
12    3
13    1
14    1
15    3
16    3
17    2
18    3
19    2
20    4

这篇关于R 返回每行最小列的索引的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！