dplyr與命令（）產生錯誤的訂單

鑑於以下data.frame，我想要爲每個組的數字的順序。dplyr與命令（）產生錯誤的訂單

df 
    group  numbers 
1  A -0.80097537 
2  B -0.69498701 
3  C 0.55627105 
4  D -0.05810593 
5  A -1.41748489 
6  B 0.30198594 
7  C 1.11918243 
8  D 0.02595183 
9  A 1.74417489 
10  B 0.42435785 
11  C 0.75889049 
12  D -2.21025222 
13  A 0.57149543 
14  B 0.77944238 
15  C 3.04021182 
16  D -0.14157181 
17  A -0.29213733 
18  B -1.00858701 
19  C 1.49959112 
20  D -0.57532183 

structure(list(group = structure(c(1L, 2L, 3L, 4L, 1L, 2L, 3L, 
4L, 1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L), class = "factor", .Label = c("A", 
"B", "C", "D")), numbers = c(-0.800975371801324, -0.694987011133934, 
0.556271051640264, -0.0581059266921911, -1.41748489222262, 0.301985943949874, 
1.11918243487368, 0.0259518302570701, 1.74417489077084, 0.424357848275249, 
0.758890492984891, -2.2102522179535, 0.571495432426037, 0.779442380219119, 
3.04021182328692, -0.141571814386413, -0.292137333159453, -1.00858701158259, 
1.49959111842538, -0.575321833031783)), .Names = c("group", "numbers" 
), row.names = c(NA, -20L), class = "data.frame")

不知何故爲組d的順序不正確：

df %>% 
group_by(group) %>% 
mutate(x=order(numbers)) %>% 
arrange(group, x) 

Source: local data frame [20 x 3] 
Groups: group [4] 

    group  numbers  x 
    <fctr>  <dbl> <int> 
1  A -1.41748489  1 
2  A -0.80097537  2 
3  A -0.29213733  3 
4  A 0.57149543  4 
5  A 1.74417489  5 
6  B 0.30198594  1 
7  B 0.42435785  2 
8  B 0.77944238  3 
9  B -1.00858701  4 
10  B -0.69498701  5 
11  C 0.55627105  1 
12  C 0.75889049  2 
13  C 1.11918243  3 
14  C 1.49959112  4 
15  C 3.04021182  5 
16  D -0.14157181  1 
17  D -0.57532183  2 
18  D -0.05810593  3 
19  D -2.21025222  4 
20  D 0.02595183  5

因此具體地，線19的順序是錯誤的。任何關於我的誤解的想法？

來源

2017-02-20 c0bra

'df％>％group_by（group）％>％arrange（group，numbers）'給出正確的輸出。你可以使用'dense_rank'而不是'order'，即'df％>％group_by（group）％>％mutate（x = dense_rank（numbers））％>％arrange（group，x）' – akrun

但是爲什麼order和dense_rank給出不同的結果？ – c0bra

只要做到這一點'％>％group_by（group）％>％mutate（x = order（order（numbers）））％>％arrange（group，x）' – akrun

order給出值的順序。在這裏，我們需要rank

library(tidyverse) 
df %>% 
    group_by(group) %>% 
    mutate(x=dense_rank(numbers)) %>% 
    arrange(group, x)

來源

2017-02-20 10:19:56 akrun

[rank-and-order-in-r] （http://stackoverflow.com/questions/12289224/rank-and-order-in-r）幫助我理解。來自R的簡單'等級'似乎也足夠了。 – c0bra

@ c0bra是的，這是真的，但如果有關係，那麼'rank'將進入默認模式 – akrun

dplyr與命令（）產生錯誤的訂單

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