Program_5

Author

Asha

Implement an R program to create a histogram illustrating the distribution of a continuous variable, wit overlays of density curves for each group, using ggplot2

Step 1:Load required library

# Load ggplot2 package for visualization
library(ggplot2)

Step 2:Explore the inbuilt dataset

# Use the built-in 'iris' dataset
# `Petal.Length` is a continuous variable
#` Species` is categorical grouping variable
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
head(iris,n=2)
  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
tail(iris)
    Sepal.Length Sepal.Width Petal.Length Petal.Width   Species
145          6.7         3.3          5.7         2.5 virginica
146          6.7         3.0          5.2         2.3 virginica
147          6.3         2.5          5.0         1.9 virginica
148          6.5         3.0          5.2         2.0 virginica
149          6.2         3.4          5.4         2.3 virginica
150          5.9         3.0          5.1         1.8 virginica
tail(iris,n=2)
    Sepal.Length Sepal.Width Petal.Length Petal.Width   Species
149          6.2         3.4          5.4         2.3 virginica
150          5.9         3.0          5.1         1.8 virginica

Step 3: Intializing the plot

# start ggplot with iris dataset
# Map Petal.length to x-axis and fill by Species

p <- ggplot(data= iris,aes(x= Petal.Length,fill=Species))
p

p<- p+geom_histogram(aes(y= ..density..),
alpha=0.4,
position="identity",
bins= 30 )
p
Warning: The dot-dot notation (`..density..`) was deprecated in ggplot2 3.4.0.
ℹ Please use `after_stat(density)` instead.

#Overlay density curves for each group
p <- p +
geom_density(aes(color=Species),
size=1.2)
Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
ℹ Please use `linewidth` instead.
p

# add title and axis labels, and apply clean theme
p <- p + labs(
title="Distribution of Petal Length with Group-wise Density Curves",
x="Petal Length",
y= "Density")+
theme_minimal()
p

# add title and axis labels, and apply clean theme
p <- p + labs(
title="Distribution of Petal Length with Group-wise Density Curves",
x="Petal Length",
y= "Density")+
theme_minimal()+
theme(legend.position='top')
p