r - 不为因子列运行的情况

Question

这个问题在这里已经有了答案:





case_when in mutate pipe

(6 个回答)


9 个月前关闭。




这似乎很公平，也许是一个错误，或者我遗漏了一些非常基本的东西。我尝试将 Species 转换为二进制变量 & 因此使用 case when 进行简单操作，但是收到不确定应该出现的错误。

 iris %>% 
   dplyr::mutate(Species=as.factor(Species),
     Species=case_when(Species=="setosa"~"virginica",
                       TRUE~Species))


Error: Problem with `mutate()` input `Species`.
x must be a character vector, not a `factor` object.
i Input `Species` is `case_when(Species == "setosa" ~ "virginica", TRUE ~ Species)`.

session 信息的详细信息

 sessionInfo()
R version 4.0.3 (2020-10-10)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 17763)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

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

other attached packages:
 [1] conflicted_1.0.4 extrafontdb_1.0  extrafont_0.17   forcats_0.5.0   
 [5] purrr_0.3.4      readr_1.4.0      tidyr_1.1.2      tibble_3.0.4    
 [9] tidyverse_1.3.0  ggplot2_3.3.2    dplyr_1.0.2      stringr_1.4.0   

loaded via a namespace (and not attached):
 [1] qpdf_1.1           xfun_0.19          tidyselect_1.1.0  
 [4] haven_2.3.1        snakecase_0.11.0   colorspace_1.4-1  
 [7] vctrs_0.3.4        generics_0.1.0     usethis_1.6.3     
[10] htmltools_0.5.0    yaml_2.2.1         utf8_1.1.4        
[13] rlang_0.4.8        pillar_1.4.6       glue_1.4.2        
[16] withr_2.3.0        DBI_1.1.0          dbplyr_2.0.0      
[19] modelr_0.1.8       readxl_1.3.1       lifecycle_0.2.0   
[22] munsell_0.5.0      gtable_0.3.0       cellranger_1.1.0  
[25] rvest_0.3.6        memoise_1.1.0      evaluate_0.14     
[28] knitr_1.30         curl_4.3           fansi_0.4.1       
[31] Rttf2pt1_1.3.8     broom_0.7.2        pdftools_2.3.1    
[34] Rcpp_1.0.5         scales_1.1.1       backports_1.2.0   
[37] jsonlite_1.7.1     fs_1.5.0           hms_0.5.3         
[40] askpass_1.1        digest_0.6.27      stringi_1.5.3     
[43] grid_4.0.3         cli_2.1.0          tools_4.0.3       
[46] magrittr_1.5       crayon_1.3.4       pkgconfig_2.0.3   
[49] ellipsis_0.3.1     xml2_1.3.2         reprex_0.3.0      
[52] lubridate_1.7.9    tidytuesdayR_1.0.1 assertthat_0.2.1  
[55] rmarkdown_2.5      httr_1.4.2         rstudioapi_0.12   
[58] R6_2.5.0           compiler_4.0.3    

Answer 1

使用 case_when关于因子变量有点棘手。case_when is type strict 意味着所有值都应该评估为相同的类型。您拥有的第一个值是字符类型(“virginica”)和 TRUE值的类型是 factor因此你会在那里得到一个类型不匹配错误。此外，所有值都应具有与原始数据相同水平的因子。因此，您可以合并所有这些更改:

library(dplyr)

iris %>% 
  mutate(Species=case_when(Species == "setosa" ~ 
                           factor("virginica", levels = unique(.$Species)),
                           TRUE ~ Species))