Boxplot

The code to create a boxplot is the following:

boxplot(data, main = "Title", xlab = "x-axis", col = "", border= "", horizontal = TRUE)

where data is the name of your dataframe.

Here, you can specify the box color in col and the border color in border. If you want to have the boxplot to be vertical, set horizontal=FALSE.

Example:

df <- read.csv('Data/NHANES.csv')

boxplot(df$Height, main='Height in the U.S.', xlab='Height (cm)', col='lightgoldenrod1',
        border = 'lightgoldenrod4', horizontal=TRUE)

Comparative boxplot

You can create a comparative boxplot by using the following code:

boxplot(numerical~categorical, data = df, main = "Title", 
xlab="x-axis", ylab = "y-axis", col = "", border= "", horizontal=TRUE)

numerical is the column name that includes the numerical value that you would like to visualize in the boxplot and categorical is the column name that includes the categorical value that includes the name of the group.

For example:

boxplot(Height~Gender, data=df, main='Height in the U.S.', xlab='Height (cm)', col='lightskyblue1',
        ylab='Gender',border = 'lightslateblue', horizontal=TRUE)

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