so.Hist ignores common_norm=True for the "density" aggregate statistic

[defiori]

Current behaviour

so.Hist ignores common_norm=True for the "density" aggregate statistic. sns.histplot works correctly.

Desired behaviour

so.Hist should take into account common_norm when applying density normalization. The objects interface adds some neat functionality for normalizing per facet. Currently it can't be used with "density".

Examples

I would expect the below examples to produce the same histogram.

(
    so.Plot(
        penguins, 
        x='bill_length_mm', 
        color='species'
    )
    .add(
        so.Bars(), 
        so.Hist(
            stat='density',
            common_norm=True,
        ), 
    )
)

sns.histplot(
    data=penguins, 
    x='bill_length_mm', 
    hue='species',
    stat='density',
    common_norm=True,
)

Versions

• seaborn 0.13.2
• matplotlib 3.8.2
• pandas 2.2.0