Refill the NAs for a 'na.action' Object

For a na.action object, use the indices of where NAs were removed to refill the object back to its original size with NAs in the appropriate positions.

Usage

na.refill(object, ...)

Arguments

object: a na.action object (atomic vector, matrix or data.frame).
...: further arguments special methods could require.

Value

vector, matrix or data.frame with the indices from na.action refilled with NAs. rownames and colnames are preserved.

If the object given is not of those types, or not a na.action object, it is returned unchanged.

Details

For objects where na.omit removes whole rows (e.g., matrices, data.frames), the information about that row is lost, so na.refill will refill those entire rows with NAs.

Examples

x <- c(1, 2, NA, 4, NA, 6)
na_x <- na.omit(x)
na_x
#> [1] 1 2 4 6
#> attr(,"na.action")
#> [1] 3 5
#> attr(,"class")
#> [1] "omit"
na.refill(na_x)
#> [1]  1  2 NA  4 NA  6
#> attr(,"na.action")
#> [1] 3 5
#> attr(,"class")
#> [1] "refilled"

m <- matrix(1:9, 3, 3)
m[c(1, 3), 1:2] <- NA
dimnames(m) <- list(c("r1", "r2", "r3"), c("a", "b", "c"))
na_m <- na.omit(m)
na_m
#>    a b c
#> r2 2 5 8
#> attr(,"na.action")
#> r1 r3 
#>  1  3 
#> attr(,"class")
#> [1] "omit"
na.refill(na_m) # previous data in NA row is lost
#>     a  b  c
#> r1 NA NA NA
#> r2  2  5  8
#> r3 NA NA NA
#> attr(,"na.action")
#> r1 r3 
#>  1  3 
#> attr(,"class")
#> [1] "refilled"

df <- data.frame(x = 1:5, y = c("a", NA, "c", "d", NA))
na_df <- na.omit(df)
na_df
#>   x y
#> 1 1 a
#> 3 3 c
#> 4 4 d
na.refill(na_df)
#>    x    y
#> 1  1    a
#> 2 NA <NA>
#> 3  3    c
#> 4  4    d
#> 5 NA <NA>