kuva ecdf
Empirical cumulative distribution function. Plots F(x) = P(X ≤ x) as a right-continuous step function. Multi-group plots overlay one curve per group; use --confidence-band to show DKW 95% bands.
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 |
--color-by <COL> | — | Group by this column; one curve per unique value |
--complementary | off | Plot 1 - F(x) (survival / exceedance probability) |
--confidence-band | off | DKW 95% confidence band around each curve |
--rug | off | Tick marks at each data point below the x-axis |
--percentile-lines <LIST> | — | Comma-separated F values, e.g. 0.25,0.5,0.75 |
--markers | off | Circle at each step endpoint (useful for small n) |
--smooth | off | KDE-integrated smooth CDF instead of step function |
--stroke-width <F> | 1.5 | Line stroke width |
# Basic ECDF
kuva ecdf data.tsv --value score --x-label "Score" --y-label "F(x)" --title "ECDF"
# Multi-group with confidence bands
kuva ecdf data.tsv --value expression --color-by group --confidence-band
# Complementary CDF with log x-axis (read lengths)
kuva ecdf reads.tsv --value length --complementary --rug --log-x \
--x-label "Read length (bp)" --y-label "Fraction ≥ length"
# Percentile markers + rug
kuva ecdf data.tsv --value score --percentile-lines 0.25,0.5,0.75 --markers --rug
# Smooth CDF
kuva ecdf data.tsv --value score --color-by group --smooth
See also: Shared flags — output, appearance, axes, log scale.