Get Number of Missing Values by Group in R (Example Code)
In this tutorial, I’ll show how to get the number of missing values by group in the R programming language.
Creation of Example Data
data(iris) # Load & modify iris data set iris_NA <- iris[c(1:3, 51:53, 101:103), c(1, 5)] iris_NA$Sepal.Length[c(2, 4, 6, 7)] <- NA iris_NA # Sepal.Length Species # 1 5.1 setosa # 2 NA setosa # 3 4.7 setosa # 51 NA versicolor # 52 6.4 versicolor # 53 NA versicolor # 101 NA virginica # 102 5.8 virginica # 103 7.1 virginica |
data(iris) # Load & modify iris data set iris_NA <- iris[c(1:3, 51:53, 101:103), c(1, 5)] iris_NA$Sepal.Length[c(2, 4, 6, 7)] <- NA iris_NA # Sepal.Length Species # 1 5.1 setosa # 2 NA setosa # 3 4.7 setosa # 51 NA versicolor # 52 6.4 versicolor # 53 NA versicolor # 101 NA virginica # 102 5.8 virginica # 103 7.1 virginica
Example: Counting Number of NA Values by Group Using aggregate() Function
aggregate(Sepal.Length ~ Species, # Returning number of NAs by group data = iris_NA, function(x) {sum(is.na(x))}, na.action = NULL) # Species Sepal.Length # 1 setosa 1 # 2 versicolor 2 # 3 virginica 1 |
aggregate(Sepal.Length ~ Species, # Returning number of NAs by group data = iris_NA, function(x) {sum(is.na(x))}, na.action = NULL) # Species Sepal.Length # 1 setosa 1 # 2 versicolor 2 # 3 virginica 1
Related Articles
In the following, you may find some further resources on topics such as data inspection, time objects, and counting.