使用来自 dplyr 的 Unite 组合多个字符列时 na.rm = TRUE 的问题

Question

When trying to combine multiple character columns using unite from dplyr, the na.rm = TRUE option does not remove NA.

Step by step:

1. Original dataset has 5 columns word1:word5 Image of the original data
2. Looking to combine word1:word5 in a single column using code:

    data_unite_5 <-  data_original_5 %>%
        unite("pentawords", word1:word5, sep=" ", na.rm=TRUE, remove=FALSE)

• Here's an image of the output: data_unite_5

3. I've tried using mutate_if(is.factor, as.character) but that did not work.

Any suggestions would be appreciated.

Answer 1

You have misinterpreted how the na.rm argument works for unite . Following the examples on the tidyverse page here , z is the unite of x and y .

With na.rm = FALSE

#>   z     x     y    
#>   <chr> <chr> <chr>
#> 1 a_b   a     b    
#> 2 a_NA  a     NA   
#> 3 NA_b  NA    b    
#> 4 NA_NA NA    NA   

With na.rm = TRUE

#>   z     x     y    
#>   <chr> <chr> <chr>
#> 1 "a_b" a     b    
#> 2 "a"   a     NA   
#> 3 "b"   NA    b    
#> 4 ""    NA    NA  

Hence na.rm determines how NA values appear in the assembled strings ( pentrawords ) it does not drop rows from the data.

If you were wanting to remove the fourth row of the dataset, I would recommend filter .

data_unite_5 <- data_original_5 %>%
  unite("pentawords", word1:word5, sep =" " , na.rm = TRUE, remove = FALSE) %>%
  filter(pentawords != "")

Which will exclude from your output all empty strings.