R Compute Sums of Columns & Rows in Data Frame or Matrix (2 Examples)
In this tutorial, I’ll explain how to calculate row and column sums in R.
Creating Example Data
data(iris) # Load iris data iris_num <- iris[ , 1:4] # Extract numeric columns head(iris_num) # Head of numeric iris # Sepal.Length Sepal.Width Petal.Length Petal.Width # 1 5.1 3.5 1.4 0.2 # 2 4.9 3.0 1.4 0.2 # 3 4.7 3.2 1.3 0.2 # 4 4.6 3.1 1.5 0.2 # 5 5.0 3.6 1.4 0.2 # 6 5.4 3.9 1.7 0.4 |
data(iris) # Load iris data iris_num <- iris[ , 1:4] # Extract numeric columns head(iris_num) # Head of numeric iris # Sepal.Length Sepal.Width Petal.Length Petal.Width # 1 5.1 3.5 1.4 0.2 # 2 4.9 3.0 1.4 0.2 # 3 4.7 3.2 1.3 0.2 # 4 4.6 3.1 1.5 0.2 # 5 5.0 3.6 1.4 0.2 # 6 5.4 3.9 1.7 0.4
Example 1: Applying colSums Function to Compute Column Sums
colSums(iris_num) # Use colSums() # Sepal.Length Sepal.Width Petal.Length Petal.Width # 876.5 458.6 563.7 179.9 |
colSums(iris_num) # Use colSums() # Sepal.Length Sepal.Width Petal.Length Petal.Width # 876.5 458.6 563.7 179.9
Example 2: Applying rowSums Function to Compute Row Sums
rowSums(iris_num) # Use rowSums() # [1] 10.2 9.5 9.4 9.4 10.2 11.4 9.7 10.1 8.9 9.6 10.8 10.0 9.3 8.5 ... |
rowSums(iris_num) # Use rowSums() # [1] 10.2 9.5 9.4 9.4 10.2 11.4 9.7 10.1 8.9 9.6 10.8 10.0 9.3 8.5 ...
Further Resources & Related Tutorials
You may find some related R programming tutorials on topics such as variables and the dplyr package in the following list: