Move All NA Values to the End of the Rows or Columns of a Matrix

Moves all of the NA values in the rows or columns of a matrix to the end of the respective rows or columns.

naLast(inmat, by = "row", outList = FALSE, fill = NA)

Arguments

inmat	The input matrix.
by	Should be either "row" or "col", depending on if you want to shift non-NA values left or up.
outList	Logical. Do you just want a list of the non-NA values? Defaults to FALSE.
fill	While you're at it, do you want to replace NA with some other value?

Value

Either a matrix with the same dimensions as the input matrix or a list with the same number of rows or columns as the input matrix (depending on the choice made in by).

References

http://stackoverflow.com/q/23008142/1270695

Author

Ananda Mahto

Examples

set.seed(1)
m <- matrix(sample(25, 20, TRUE), ncol = 4,
            dimnames = list(letters[1:5], LETTERS[1:4]))
m[sample(prod(dim(m)), prod(dim(m)) * .6)] <- NA

m
#>    A  B  C  D
#> a NA 23  1 14
#> b NA 11 NA NA
#> c NA 14 21  7
#> d NA NA NA NA
#> e NA NA 22 NA

naLast(m, by = "row")
#>    A  B  C  D
#> a 23  1 14 NA
#> b 11 NA NA NA
#> c 14 21  7 NA
#> d NA NA NA NA
#> e 22 NA NA NA
naLast(m, by = "col")
#>    A  B  C  D
#> a NA 23  1 14
#> b NA 11 21  7
#> c NA 14 22 NA
#> d NA NA NA NA
#> e NA NA NA NA
naLast(m, by = "col", outList = TRUE)
#> [[1]]
#> named integer(0)
#> 
#> [[2]]
#>  a  b  c 
#> 23 11 14 
#> 
#> [[3]]
#>  a  c  e 
#>  1 21 22 
#> 
#> [[4]]
#>  a  c 
#> 14  7 
#>