长变量名称在dplyr中失败 [英] Long variable name fails in dplyr

问题描述

长度超过39个字符的字符串在dplyr中失败，返回错误：Error：index out of bounds。

我错过了什么，还是这个错误？

40个字符不起作用：

 库（dplyr）
 
名称（iris）[5] < - vvv_5vvv10vvv15vvv20vvvvvvvvvvvvvvvvvv
 
 iris％>％dplyr :: group_by（vvv_5vvv10vvv15vvv20vvvvvvvvvvvvvvvvvvv）％>％
 
 dplyr :: summarize（n（））
  

给我错误：
错误：索引出边界

< h2> 39个字符作品：

 名称（iris）[5]<  - vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vv39
 
 iris％>％dplyr :: group_by（vvv_5vvv10vvvvvvvvvvvvvvvvvvvvvvvvvvv39）％>％
 
 dplyr :: summarize（n（））
  

工作正常。给我这个（想要的）输出

 来源：本地数据框架[3 x 2] 
 
 vvv_5vvv10vvv15vvv20vvvvvvvvvvvvvvvvv39 n（）
 1 setosa 50 
 2 versicolor 50 
 3 virginica 5 
  

SessionInfo（）

 > sessionInfo（）
 R版本3.1.1（2014-07-10）
平台：x86_64-w64-mingw32 / x64（64位）
 
语言环境：
 [1] LC_COLLATE = Denmark_Denmark.1252 LC_CTYPE = Denmark_Denmark.1252 LC_MONETARY = Denmark_Denmark.1252 LC_NUMERIC = C 
 [5] LC_TIME = Denmark_Denmark.1252 
 
附加的基本包：
 [1]统计图形grDevices utils数据集方法base 
 
其他附加的包：
 [1] dplyr_0.3.0.2 
 
通过命名空间加载（而不是附加）：
 [1] assertthat_0.1 DBI_0.3.1 lazyeval_0.1.9 magrittr_1.0.1 parallel_3.1.1 Rcpp_0.11.3 tools_3.1.1 
  

解决方案

这似乎是 一个已知问题 ，修正为 dplyr 0.3.1 。从@romainfrancois在发帖中的回复：

发生在这里[...]

  new_groups<  -  lazyeval :: auto_name（new_groups）
  

因为：

  lazyeval :: auto_name 
函数（x，max_width = 40）
 {
名称（x）<  -  auto_names（x，max_width = max_width）
x 
} 
< environment：namespace：lazyeval> 
  

更新

在 dplyr 0.4.0 group_by（）支持超过39个字符的变量，这要归功于 lazyeval 中的修正：

 库（dplyr）
＃具有40个字符的变量名
名称（iris）[5]<  - vvv_5vvv10vvvvvvvvvvvvvvvvvvvvvvvvvvv
 
 iris％>％
 group_by（vvv_5vvv10vvvvvvvvvvvvvvvvvvvvvvvvvv40）％>％
总结（n（））
＃ vvv_5vvv10vvv15vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
Strings longer than 39 characters fail in dplyr, returning the error: "Error: index out of bounds". 

Am I missing something or is this a bug?

40 characters does not work:

library(dplyr)

names(iris)[5]   <- "vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vvv40"

iris %>% dplyr::group_by(  vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vvv40 ) %>%

  dplyr::summarise( n() )
Gives me the error:
Error: index out of bounds

39 characters works:

names(iris)[5]   <- "vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vv39"

iris %>% dplyr::group_by(  vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vv39 ) %>%

  dplyr::summarise( n() )
Works fine. gives me this (desired) output
Source: local data frame [3 x 2]

      vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vv39 n()
    1                                  setosa  50
    2                              versicolor  50
    3                               virginica  5
SessionInfo()
> sessionInfo()
R version 3.1.1 (2014-07-10)
Platform: x86_64-w64-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=Danish_Denmark.1252  LC_CTYPE=Danish_Denmark.1252    LC_MONETARY=Danish_Denmark.1252 LC_NUMERIC=C                   
[5] LC_TIME=Danish_Denmark.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] dplyr_0.3.0.2

loaded via a namespace (and not attached):
[1] assertthat_0.1 DBI_0.3.1      lazyeval_0.1.9 magrittr_1.0.1 parallel_3.1.1 Rcpp_0.11.3    tools_3.1.1  

解决方案
This seems to be a known issue, to be fixed in dplyr 0.3.1. From the reply by @romainfrancois in the post:

"It happens here [...]
new_groups <- lazyeval::auto_name(new_groups)
because:
lazyeval::auto_name
function (x, max_width = 40)
{
    names(x) <- auto_names(x, max_width = max_width)
    x
}
<environment: namespace:lazyeval>
"

Update

In dplyr 0.4.0 "group_by() supports variables with more than 39 characters thanks to a fix in lazyeval":
library(dplyr)
# Variable name with 40 characters
names(iris)[5] <- "vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vvv40"

iris %>% 
  group_by(vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vvv40) %>%
  summarise(n())
#   vvv_5vvv10vvv15vvv20vvv25vvv30vvv35vvv40 n()
# 1                                   setosa  50
# 2                               versicolor  50
# 3                                virginica  50


                        
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