Boxes and violins

Introduction to Data Visualization with Julia

Gustavo Vieira Suñe

Data Analyst

Histograms with many categories

A stacked histogram displaying the distribution of onion and wheat prices.

A stacked histogram displaying the distribution of onion, potato, tomato and wheat prices.

Hard to compare many categories

Box plots

A box plot displaying the distribution of onion, potato, tomato and wheat prices.

Boxes of product

using StatsPlots


boxplot(
    # Categories in x-axis
    kerala[:, :Commodity],
    # Values in y-axis
    kerala[:, :Price],

    color=:darkorange,
    label=false,
)
ylabel!("Price (Rupees)")

A box plot displaying the distribution of onion, potato, tomato and wheat prices.

Hiding outliers

using StatsPlots

boxplot(
    # Categories in x-axis
    kerala[:, "Commodity"],
    # Values in y-axis
    kerala[:, :Price],
    color=:darkorange,
    label=false,

    # Hide outliers
    outliers=false,

)
ylabel!("Price (Rupees)")

A box plot displaying the distribution of onion, potato, tomato and wheat prices, with outliers omitted.

Violin plots

A violin plot displaying the distribution of onion, potato, tomato and wheat prices.

Distributions with violin plot

# Create violin plot
violin(
    # Categories in x-axis
    kerala[:, :Commodity],
    # Values in y-axis
    kerala[:, :Price],

    # Remove lines
    linewidth=0,

    color=:darkorange,
    label=false,
)
ylabel!("Price (Rupees)")

A violin plot displaying the distribution of onion, potato, tomato and wheat prices.

Boxes or violins?

Box plots
- Central tendency, spread & skewness
- Emphasize outliers

A box plot displaying the distribution of onion, potato, tomato and wheat prices.

Violin plots
- Details of distribution
- Shape is relevant (e.g., multimodal)

A violin plot displaying the distribution of onion, potato, tomato and wheat prices.

Let's practice!

Introduction to Data Visualization with Julia