Data Science – Examine Data Spread using Histogram and Density Plot

Code Sample – Draw Histogram and Density Plot

Histrogram and density plot are very useful for examining the spread of a data variable. Following R commands with ggplot package helps in drawing histogram and density plots. As I am explaining with ggplot package, I am using diamonds data which comes with ggplot package. Pay attention to some of the following:

• Draw Histogram: Command “ggplot(data) + geom_histogram(aes(x=variableName))” is used to draw the histogram. One could also provide binwidth as an additional parameter to geom_histogram function
• Draw Density Plot: Command “ggplot(data) + geom_density(aes(x=variableName))” is used to create the density plot.

# Histogram to evaluate the spread of carat data
ggplot(diamonds) + geom_histogram(aes(x=carat))

# Density plot to evaluate the spread of carat data
ggplot(data=diamonds) + geom_density(aes(x=carat))