prg11

Write an R program to generate a basic box plot, enhanced with notches and outliers, and grouped by a categorical variable, using ggplot2.

Step 1 : Load required Package

library(ggplot2)

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

Step 2 : Use an Inbuilt Dataset

We will use the in-built iris dataset.This Dataset contains measurements of sepal and Petal - setosa - versicolor - virginica

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

str(iris)

'data.frame':   150 obs. of  5 variables:
 $ Sepal.Length: num  5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...
 $ Sepal.Width : num  3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ...
 $ Petal.Length: num  1.4 1.4 1.3 1.5 1.4 1.7 1.4 1.5 1.4 1.5 ...
 $ Petal.Width : num  0.2 0.2 0.2 0.2 0.2 0.4 0.3 0.2 0.2 0.1 ...
 $ Species     : Factor w/ 3 levels "setosa","versicolor",..: 1 1 1 1 1 1 1 1 1 1 ...

Step 3 : Create a notched Box Plot Grouped by Species

We now create a box plot for Sepal.Length,grouped by Species . We’ll enhance the plot using:- Notches to show the confidence interval around the median-OUtlier highlighting using color and shape - Aesthetic enhancements like fill color and theme.

p <- ggplot(iris, aes(x= Species , y= Sepal.Length)) +
   geom_boxplot(
            notch = TRUE,
            notchwidth = 0.6 ,
            outlier.colour = "red",
            outlier.shape = 16 ,
            fill = "skyblue",
            alpha = 0.7
          ) 
p

p <- p + 
  labs(
    title = "Sepal length distribution by iris species",
    subtitle = "Box plot with notches and outlier highlighting",
    x = "Species",
    y = "Sepal.Length"
    ) +
  theme_minimal()
p

p <- ggplot(iris, aes(x= Species , y= Sepal.Width)) +
   geom_boxplot(
            notch = TRUE,
            notchwidth = 0.6 ,
            outlier.colour = "red",
            outlier.shape = 16 ,
            fill = "skyblue",
            alpha = 0.7
          ) 
p

p <- ggplot(iris, aes(x= Species , y= Petal.Length)) +
   geom_boxplot(
            notch = TRUE,
            notchwidth = 0.6 ,
            outlier.colour = "red",
            outlier.shape = 16 ,
            fill = "skyblue",
            alpha = 0.7
          ) 
p

p <- ggplot(iris, aes(x= Species , y= Petal.Width)) +
   geom_boxplot(
            notch = TRUE,
            notchwidth = 0.6 ,
            outlier.colour = "red",
            outlier.shape = 16 ,
            fill = "skyblue",
            alpha = 0.7
          ) 
p

Notch went outside hinges
ℹ Do you want `notch = FALSE`?