Create Consecutive Group ID Number in R (Example Code)
This article shows how to create an ID number by group in the R programming language.
Creation of Example Data
data(iris) # Example data head(iris) # Head of example data # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 1 5.1 3.5 1.4 0.2 setosa # 2 4.9 3.0 1.4 0.2 setosa # 3 4.7 3.2 1.3 0.2 setosa # 4 4.6 3.1 1.5 0.2 setosa # 5 5.0 3.6 1.4 0.2 setosa # 6 5.4 3.9 1.7 0.4 setosa |
data(iris) # Example data head(iris) # Head of example data # Sepal.Length Sepal.Width Petal.Length Petal.Width Species # 1 5.1 3.5 1.4 0.2 setosa # 2 4.9 3.0 1.4 0.2 setosa # 3 4.7 3.2 1.3 0.2 setosa # 4 4.6 3.1 1.5 0.2 setosa # 5 5.0 3.6 1.4 0.2 setosa # 6 5.4 3.9 1.7 0.4 setosa
Example: Creating Group ID Variable
iris_new <- transform(iris, my_id = as.numeric(factor(Species))) # Adding ID column head(iris_new) # Head of data with ID # Sepal.Length Sepal.Width Petal.Length Petal.Width Species my_id # 1 5.1 3.5 1.4 0.2 setosa 1 # 2 4.9 3.0 1.4 0.2 setosa 1 # 3 4.7 3.2 1.3 0.2 setosa 1 # 4 4.6 3.1 1.5 0.2 setosa 1 # 5 5.0 3.6 1.4 0.2 setosa 1 # 6 5.4 3.9 1.7 0.4 setosa 1 |
iris_new <- transform(iris, my_id = as.numeric(factor(Species))) # Adding ID column head(iris_new) # Head of data with ID # Sepal.Length Sepal.Width Petal.Length Petal.Width Species my_id # 1 5.1 3.5 1.4 0.2 setosa 1 # 2 4.9 3.0 1.4 0.2 setosa 1 # 3 4.7 3.2 1.3 0.2 setosa 1 # 4 4.6 3.1 1.5 0.2 setosa 1 # 5 5.0 3.6 1.4 0.2 setosa 1 # 6 5.4 3.9 1.7 0.4 setosa 1