Column of a tibble won't arrange by alphabetical order-CodePudding

I have a tibble as shown below extracted from a larger data set. I would like to sort the Species column by alphabetical order. But for some reason beyond my understanding i cannot get this to work. Any ideas what's going on?

I tried the following methods

arrange(dummy, Species)
dummy[order(dummy$Species),]

Sample data set:

# A tibble: 4 × 3
# Groups:   Species [4]
  Species                M     mean.active.prop
  <fct>                  <chr>            <dbl>
1 Caribbean reef shark   01                 1  
2 Nurse shark            03                 0.9
3 Lemon shark (adult)    06                 0.8
4 Lemon shark (juvenile) 04                 0.7

> class(dummy)
[1] "grouped_df" "tbl_df"     "tbl"        "data.frame"

dput output:

dummy <- structure(list(Species = structure(1:4, levels = c("Caribbean reef shark", 
"Nurse shark", "Lemon shark (adult)", "Lemon shark (juvenile)", 
"Tiger shark", "Great hammerhead shark", "Bull shark", "Blacktip shark", 
"Southern stingray"), class = "factor"), M = c("01", "03", "06", 
"04"), mean.active.prop = c(1, 0.9, 0.8, 0.7)), class = c("grouped_df", 
"tbl_df", "tbl", "data.frame"), row.names = c(NA, -4L), groups = structure(list(
    Species = structure(1:4, levels = c("Caribbean reef shark", 
    "Nurse shark", "Lemon shark (adult)", "Lemon shark (juvenile)", 
    "Tiger shark", "Great hammerhead shark", "Bull shark", "Blacktip shark", 
    "Southern stingray"), class = "factor"), .rows = structure(list(
        1L, 2L, 3L, 4L), ptype = integer(0), class = c("vctrs_list_of", 
    "vctrs_vctr", "list"))), class = c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -4L), .drop = TRUE))

CodePudding user response：

Since you want the result in alphabetical order you need to convert Species to character and apply arrange:

> dummy %>% 
    mutate(Species = as.character(Species)) %>% 
    arrange(Species)
# A tibble: 4 × 3
# Groups:   Species [4]
  Species                M     mean.active.prop
  <chr>                  <chr>            <dbl>
1 Caribbean reef shark   01                 1  
2 Lemon shark (adult)    06                 0.8
3 Lemon shark (juvenile) 04                 0.7
4 Nurse shark            03                 0.9

CodePudding user response：

Species is a factor column, it's sorted according to the underlying numeric, convert to character and you'll be able to sort just fine.

dummy
#> # A tibble: 4 × 3
#>   Species                M     mean.active.prop
#>   <fct>                  <chr>            <dbl>
#> 1 Caribbean reef shark   01                 1  
#> 2 Nurse shark            03                 0.9
#> 3 Lemon shark (adult)    06                 0.8
#> 4 Lemon shark (juvenile) 04                 0.7



levels(dummy$Species)
#> [1] "Caribbean reef shark"   "Nurse shark"            "Lemon shark (adult)"   
#> [4] "Lemon shark (juvenile)" "Tiger shark"            "Great hammerhead shark"
#> [7] "Bull shark"             "Blacktip shark"         "Southern stingray"

dummy[order(as.character(dummy$Species)),]
#> # A tibble: 4 × 3
#>   Species                M     mean.active.prop
#>   <fct>                  <chr>            <dbl>
#> 1 Caribbean reef shark   01                 1  
#> 2 Lemon shark (adult)    06                 0.8
#> 3 Lemon shark (juvenile) 04                 0.7
#> 4 Nurse shark            03                 0.9