kuva qq

Q-Q (quantile-quantile) plot in two modes:

  • Normal mode (default) — sample quantiles vs standard-normal theoretical quantiles with a robust Q1–Q3 reference line. Use for normality checks and comparing distribution shapes.
  • Genomic mode (--genomic) — −log₁₀(observed p) vs −log₁₀(expected p). Use for GWAS p-value calibration. Input values must be raw p-values in (0, 1].

Input: a tabular file with at least one numeric column. When --color-by is used, an additional categorical column groups the data.

FlagDefaultDescription
--value <COL>0Column of values (raw data or p-values)
--color-by <COL>Group by this column; one set of points per unique value
--genomicoffGenomic mode: input values are p-values in (0, 1]
--ci-bandoff95 % pointwise CI band around the reference diagonal
--lambdaoffAnnotate λ (genomic inflation factor); genomic mode only
--no-reference-lineHide the reference line
--marker-size <F>3.0Marker radius in pixels
--fill-opacity <F>Marker fill opacity (0–1)
# Normal Q-Q
kuva qq data.tsv --value score --title "Normal Q-Q"

# Multi-group
kuva qq data.tsv --value score --color-by group

# Genomic Q-Q
kuva qq gwas.tsv --value pvalue --genomic \
    --x-label "Expected -log10(p)" --y-label "Observed -log10(p)"

# With CI band and lambda annotation
kuva qq gwas.tsv --value pvalue --genomic --ci-band --lambda

See also: Shared flags — output, appearance, axes, log scale.