program 6

Write an R script to construct a box plot showcasing the distribution of a continous variable grouped by a categorical variable. using ggplot2’s till asethetic.

Step 1 : Load Requried Library

#Load ggplot package for visualization
library(ggplot2)

Step 2 : Load Dataset

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 ...

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 3 :

Step 3.1 : Initialize ggplot with Aesthetic Mappings

p=ggplot(data=iris,aes(x=Species,y=Petal.Width,fill=Species))
p

Step 3.2 : Add a Box plot layer

p=p+geom_boxplot()
p

Step 3.3 : Add labels and theme

p=p+labs(little="Box plot of  Petal width by Species",
         X="Species",
         Y="Petal width")+
  theme_minimal()
p