根据下一个 R 替换 df 中的值

Question

I have a df like this

             missing_1  missing_4  missing_5
1:               7dzx                    
2:        7dzxALA1085       ALA      1085
3: 7dzxALA1085ALA1085       ALA      1085
4:               7dzx                    
5:         7dzxALA156       ALA       156
6:   7dzxALA156ALA156       ALA       156

and when missing_4 and missing_5 are empty I would like to replace that values with the folowing ones in that column. So it should become:

           missing_1 missing_4 missing_5
1:               7dzx       ALA      1085      
2:        7dzxALA1085       ALA      1085
3: 7dzxALA1085ALA1085       ALA      1085
4:               7dzx       ALA       156     
5:         7dzxALA156       ALA       156
6:   7dzxALA156ALA156       ALA       156

I was thinking about a for loop but I'm not skilled enought to realize it. Thanks!

Answer 1

We could use fill from tidyr

library(dplyr)
library(tidyr)
df1 %>%
    fill(c(missing_4, missing_5), .direction = "updown")

-output

             missing_1 missing_4 missing_5
1:               7dzx       ALA      1085
2:        7dzxALA1085       ALA      1085
3: 7dzxALA1085ALA1085       ALA      1085
4:               7dzx       ALA       156
5:         7dzxALA156       ALA       156
6:   7dzxALA156ALA156       ALA       156

data

df1 <- structure(list(missing_1 = c("7dzx", "7dzxALA1085", "7dzxALA1085ALA1085", 
"7dzx", "7dzxALA156", "7dzxALA156ALA156"), missing_4 = c(NA, 
"ALA", "ALA", NA, "ALA", "ALA"), missing_5 = c(NA, 1085L, 1085L, 
NA, 156L, 156L)), class = c("data.table", "data.frame"), row.names = c(NA, 
-6L)