kuva density
Kernel density estimate of a single numeric column. Produces a smooth probability density curve; optionally fills the area underneath. Multi-group plots use one curve per group with palette colors.
Input: a tabular file with at least one numeric column. When --color-by is used, an additional categorical column drives the grouping.
| Flag | Default | Description |
|---|---|---|
--value <COL> | 0 | Column of numeric values to estimate |
--color-by <COL> | — | Group by this column; one curve per unique value |
--filled | off | Fill the area under each density curve |
--bandwidth <F> | (Silverman) | KDE bandwidth override |
--x-min <F> | — | Lower bound for KDE evaluation; boundary reflection applied at this edge |
--x-max <F> | — | Upper bound for KDE evaluation; boundary reflection applied at this edge |
Either flag can be used independently. Use --x-min 0 --x-max 1 for data bounded to [0, 1] (e.g. identity scores, β-values, allele frequencies). Use --x-min 0 alone for data that cannot be negative but has no known upper cap.
kuva density samples.tsv --value expression \
--x-label "Expression" --y-label "Density" --title "Expression distribution"
kuva density samples.tsv --value expression --color-by group --filled \
--title "Expression by group"
# Identity scores bounded to [0, 1] — prevents KDE from extending into impossible values
kuva density scores.tsv --value score --x-min 0 --x-max 1
# Counts that cannot be negative but have no upper cap
kuva density counts.tsv --value count --x-min 0
See also: Shared flags — output, appearance, axes, log scale.