Missing, missing data

Dealing With Missing Data in R

Nicholas Tierney

Statistician

Another perspective on missing data

name	time	value
robin	morning	358
robin	afternoon	534
robin	evening	100
sam	morning	139
sam	afternoon	177
blair	morning	963
blair	afternoon	962
blair	evening	929

name	afternoon	evening	morning
blair	962	929	963
robin	534	100	358
sam	177	NA	139

Explicit and implicit missing values

explicitly: They are missing with NA
implicitly: Not shown in the data, but implied

Making implicit missings explicit

tetris %>%
  tidyr::complete(name, time)

# A tibble: 9 x 3
  name  time      value
  <fct> <fct>     <dbl>
1 blair afternoon   962
2 blair evening     929
3 blair morning     963
4 robin afternoon   534
5 robin evening     100
6 robin morning     358
7 sam   afternoon   177
8 sam   evening      NA
9 sam   morning     139

Handling explicitly missing values

name	time	value
robin	morning	936
NA	afternoon	635
NA	evening	438
sam	morning	208
NA	afternoon	92
NA	evening	79
blair	morning	969
NA	afternoon	918
NA	evening	954

name	time	value
robin	morning	936
robin	afternoon	635
robin	evening	438
sam	morning	208
sam	afternoon	92
sam	evening	79
blair	morning	969
blair	afternoon	918
blair	evening	954

Handling explicitly missing values

name	time	value
robin	morning	936
NA	afternoon	635
NA	evening	438
sam	morning	208
NA	afternoon	92
NA	evening	79
blair	morning	969
NA	afternoon	918
NA	evening	954

tetris %>%
  tidyr::fill(name)

# A tibble: 9 x 3
  name  time      value
  <chr> <chr>     <dbl>
1 robin morning     936
2 robin afternoon   635
3 robin evening     438
4 sam   morning     208
5 sam   afternoon    92
6 sam   evening      79
7 blair morning     969
8 blair afternoon   918
9 blair evening     954

A Warning

tetris %>%
  tidyr::fill(name)

# A tibble: 9 x 3
  name  time      value
  <chr> <chr>     <dbl>
1 robin morning     936
2 robin afternoon   635
3 robin evening     438
4 sam   morning     208
5 sam   afternoon    92
6 sam   evening      79
7 blair morning     969
8 blair afternoon   918
9 blair evening     954

Let's practice!

Dealing With Missing Data in R