You can use the following methods to count non-NA values in R:
Method 1: Count Non-NA Values in Entire Data Frame
sum(!is.na(df))
Method 2: Count Non-NA Values in Each Column of Data Frame
colSums(!is.na(df))
Method 3: Count Non-NA Values by Group in Data Frame
library(dplyr) df %>% group_by(var1) %>% summarise(total_non_na = sum(!is.na(var2)))
The following example shows how to use each of these methods in practice with the following data frame:
#create data frame df frame(team=c('A', 'A', 'A', 'A', 'B', 'B', 'B', 'B'), points=c(12, NA, 30, 32, 20, 22, 17, NA), rebounds=c(10, 8, 9, 13, NA, 20, 8, 7)) #view data frame df team points rebounds 1 A 12 10 2 A NA 8 3 A 30 9 4 A 32 13 5 B 20 NA 6 B 22 20 7 B 17 8 8 B NA 7
Method 1: Count Non-NA Values in Entire Data Frame
The following code shows how to count the total non-NA values in the entire data frame:
#count non-NA values in entire data frame
sum(!is.na(df))
[1] 21
From the output we can see that there are 21 non-NA values in the entire data frame.
Method 2: Count Non-NA Values in Each Column of Data Frame
The following code shows how to count the total non-NA values in each column of the data frame:
#count non-NA values in each column
colSums(!is.na(df))
team points rebounds
8 6 7
From the output we can see:
- There are 8 non-NA values in the team column.
- There are 6 non-NA values in the points column.
- There are 7 non-NA values in the rebounds column.
Method 3: Count Non-NA Values by Group
The following code shows how to count the total non-NA values in the points column, grouped by the team column:
library(dplyr)
df %>%
group_by(team) %>%
summarise(total_non_na = sum(!is.na(points)))
# A tibble: 2 x 2
team total_non_na
1 A 3
2 B 3
From the output we can see:
- There are 3 non-NA values in the points column for team A.
- There are 3 non-NA values in the points column for team B.
Additional Resources
The following tutorials explain how to perform other common operations with missing values in R:
How to Find and Count Missing Values in R
How to Impute Missing Values in R