Putting a rug down

The plot we just made looks pretty good, but we can see a small hint of bi-modality between the hours of 10 and 15. Given we just are looking the blob of a density estimate it's hard to know how confident we are in that shape.

Let's alleviate this by doing a couple things.

First, lower the alpha on the density plot so we can more accurately locate these peaks using the background grid.

Next, add a rug-plot beneath the density plot using geom_rug(). To show any overlap that may occur in the rug plot set its alpha to 0.5.

The data frame you made in the last exercise: truck_speeding has already been loaded for you.

This exercise is part of the course

Visualization Best Practices in R

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Exercise instructions

Set alpha of density plot to 0.7.
Add geom_rug() to the plot.
Set alpha of rug plot to 0.5.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

ggplot(truck_speeding, aes(x = hour_of_day)) +
    # Adjust opacity to see gridlines with alpha = 0.7
    geom_density(bw = 1.5, fill = 'steelblue', ___) +
    # add a rug plot using geom_rug to see individual data points, set alpha to 0.5.
    ___ +
    labs(title = 'Citations by hour', subtitle = "Gaussian kernel SD = 1.5")

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