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 <- data.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: