prgm11.quarto

To generate a basic box plot using ggplot2, enhanced with notches and outliers, and grouped by a categorical variable using an in-built dataset in R.

Step 1: Load and explore the dataset.

library(ggplot2)

Step2 : Load built-in dataset and define function.

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 : plot boxplot.

ggplot(iris, aes(x = Species , y = Sepal.Length, ))+
  geom_boxplot(
    notch = TRUE,
    notchwidth = 0.7,
    fill = "purple",
    color = "yellow",
    outlier.color = "green",
    outlier.shape = 17,
  )+
  facet_wrap(~ Species)

  labs(title = "Box plot",
       x = "Species",
       y = "Sepal Length (cm)"
       )+
    theme_minimal()

NULL