prg9

Program 9 Implement an R script to create multiple histograms from grouped data, visualizing the distribution of a variable across different categories, using ggplot2’s facet_wrap function.

Objective

Create multiple histograms using ggplot2::facet_wrap() to visualize how a variable (e.g., Sepal.Length) is distributed across diffferent groups (e.g., Species) in a built-in R Dataset.

library(ggplot2)

Warning: package 'ggplot2' was built under R version 4.5.3

Step 1 : Load and Explore the dataset

data("iris")

head(iris)

  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

Step 2 : Create Group histograms using facet_wrap

p <- ggplot(iris, aes(x = Sepal.Length))
p

p <- p + geom_histogram(binwidth = 0.3, fill = "skyblue", color= "black") 
p

p <- p + facet_wrap(~ Species)
p

p <- p + labs(title = "Distribution of sepal length by species",
              x = "Sepal length",
              y ="Frequency"
              )
p

p <- p + theme_minimal() 
p