Diagram: quantile-quantile plot — Drawing: Adrien Taudière (CC0)

ggplot2 example: quantile-quantile plot — Adrien Taudière (CC0); R code ↓; data: Galton 1886, via HistData (Friendly et al. 2026) (GPL)

chart

quantile-quantile plot

also: QQ plot

Comparison of observed quantiles to a theoretical distribution.

diagramme quantile-quantile

aussi : droite de Henry

Comparaison des quantiles observés à ceux d'une loi théorique.

Classification

chart
points and bubbles › scatterplots
distribution

Channels

position on common scale; main: observed and theoretical quantiles

Attestation

French term: Andry, Kieffer & Lambotte, Les fondamentaux de la visualisation de données, De Boeck, 2022
English definition: ggplot2 reference

Scientific literature

OpenAlex: 1 264 papers since 1980, 38% in the last five years; mostly in Mathematics, Biochemistry, Genetics and Molecular Biology, Medicine; Wikidata

Seminal references

formalization (1968) WILK & GNANADESIKAN (1968). Probability plotting methods for the analysis for the analysis of data. Biometrika (1 498 citations)

R packages

R ggplot2::geom_qq(); GitHub 7 025 stars; last commit 2026-10; paper (33 455 citations) Avec geom_qq_line.
R qqman::qq(); GitHub 175 stars; last commit 2023-08; paper (1 135 citations)
R qqplotr::geom_qq_band(); GitHub 51 stars; last commit 2026-06; paper (58 citations)

R code of the ggplot2 example

library(ggplot2)
library(dplyr)
library(HistData)

sons <- GaltonFamilies |>
  filter(gender == "male")

p <- ggplot(sons, aes(sample = childHeight)) +
  geom_qq_line(colour = "#9b2367", linewidth = 0.6) +
  geom_qq(size = 1.2, alpha = 0.5, colour = "#535353") +
  scale_y_continuous(labels = lex_number, breaks = lex_break_breaks, expand = lex_break_expand) +
  labs(title = "Sons' heights follow the normal line except in the tails",
       subtitle = "481 sons from Galton's families, against a normal distribution",
       x = "Theoretical quantiles (standard normal)", y = "Height (inches)",
       caption = "Data: Galton 1886, via the HistData R package") +
  theme_lex_viz(break_not_zero = "y")

Sources (7)

7 occurrences in the corpus

Cite this entry

Stable addresshttps://dataviz.adrientaudiere.com/en/term/qq-plot.html

ReferenceTaudière Adrien. 2026. quantile-quantile plot. In Visualization Vocabulary, version 1.0.0. IdEst. https://dataviz.adrientaudiere.com/en/term/qq-plot.html

BibTeX

@incollection{taudiere2026-qq-plot,
  author    = {Taudière, Adrien},
  title     = {quantile-quantile plot},
  booktitle = {Visualization Vocabulary},
  year      = {2026},
  version   = {1.0.0},
  publisher = {IdEst},
  url       = {https://dataviz.adrientaudiere.com/en/term/qq-plot.html},
  note      = {CC0 1.0}
}

Page created on 2026-10-13. Text last changed on 2026-10-22. Images last changed on 2026-11-09. Numbers computed on 2026-10-22.