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Return or remove variables or observations that are completely missing

Source: R/remove_empty.R
remove_empty.Rd

These functions check which rows or columns of a data frame completely contain missing values, i.e. which observations or variables completely have missing values, and either (1) returns their indices; or (2) removes them from the data frame.

Usage

empty_columns(x)

empty_rows(x)

remove_empty_columns(x)

remove_empty_rows(x)

remove_empty(x)

Arguments

x

A data frame.

Value

  • For empty_columns() and empty_rows(), a numeric (named) vector with row or column indices of those variables that completely have missing values.

  • For remove_empty_columns() and remove_empty_rows(), a data frame with "empty" columns or rows removed, respectively.

  • For remove_empty(), both empty rows and columns will be removed.

Details

For character vectors, empty string values (i.e. "") are also considered as missing value. Thus, if a character vector only contains NA and ""``, it is considered as empty variable and will be removed. Same applies to observations (rows) that only contain NAor""`.

Examples

tmp <- data.frame(
  a = c(1, 2, 3, NA, 5),
  b = c(1, NA, 3, NA, 5),
  c = c(NA, NA, NA, NA, NA),
  d = c(1, NA, 3, NA, 5)
)

tmp
#>    a  b  c  d
#> 1  1  1 NA  1
#> 2  2 NA NA NA
#> 3  3  3 NA  3
#> 4 NA NA NA NA
#> 5  5  5 NA  5

# indices of empty columns or rows
empty_columns(tmp)
#> c 
#> 3 
empty_rows(tmp)
#> [1] 4

# remove empty columns or rows
remove_empty_columns(tmp)
#>    a  b  d
#> 1  1  1  1
#> 2  2 NA NA
#> 3  3  3  3
#> 4 NA NA NA
#> 5  5  5  5
remove_empty_rows(tmp)
#>   a  b  c  d
#> 1 1  1 NA  1
#> 2 2 NA NA NA
#> 3 3  3 NA  3
#> 5 5  5 NA  5

# remove empty columns and rows
remove_empty(tmp)
#>   a  b  d
#> 1 1  1  1
#> 2 2 NA NA
#> 3 3  3  3
#> 5 5  5  5

# also remove "empty" character vectors
tmp <- data.frame(
  a = c(1, 2, 3, NA, 5),
  b = c(1, NA, 3, NA, 5),
  c = c("", "", "", "", ""),
  stringsAsFactors = FALSE
)
empty_columns(tmp)
#> c 
#> 3