QQ Plot

Authors

[Editor] Hu Zheng;

[Contributors]

Modified

2026-01-17

Note

Hiplot website

This page is the tutorial for source code version of the Hiplot QQ Plot plugin. You can also use the Hiplot website to achieve no code ploting. For more information please see the following link:

https://hiplot.cn/basic/qqplot?lang=en

Verify whether a set of data comes from a certain distribution or whether two sets of data come from the same (family) distribution.

Setup

  • System Requirements: Cross-platform (Linux/MacOS/Windows)

  • Programming language: R

  • Dependent packages: data.table; jsonlite; grafify

# Install packages
if (!requireNamespace("data.table", quietly = TRUE)) {
  install.packages("data.table")
}
if (!requireNamespace("jsonlite", quietly = TRUE)) {
  install.packages("jsonlite")
}
if (!requireNamespace("grafify", quietly = TRUE)) {
  install.packages("grafify")
}

# Load packages
library(data.table)
library(jsonlite)
library(grafify)
sessioninfo::session_info("attached")
─ Session info ───────────────────────────────────────────────────────────────
 setting  value
 version  R version 4.5.2 (2025-10-31)
 os       Ubuntu 24.04.3 LTS
 system   x86_64, linux-gnu
 ui       X11
 language (EN)
 collate  C.UTF-8
 ctype    C.UTF-8
 tz       UTC
 date     2026-01-17
 pandoc   3.1.3 @ /usr/bin/ (via rmarkdown)
 quarto   1.8.27 @ /usr/local/bin/quarto

─ Packages ───────────────────────────────────────────────────────────────────
 package    * version date (UTC) lib source
 data.table * 1.18.0  2025-12-24 [1] RSPM
 ggplot2    * 4.0.1   2025-11-14 [1] RSPM
 grafify    * 5.1.0   2025-08-25 [1] RSPM
 jsonlite   * 2.0.0   2025-03-27 [1] RSPM

 [1] /home/runner/work/_temp/Library
 [2] /opt/R/4.5.2/lib/R/site-library
 [3] /opt/R/4.5.2/lib/R/library
 * ── Packages attached to the search path.

──────────────────────────────────────────────────────────────────────────────

Data Preparation

# Load data
data <- data.table::fread(jsonlite::read_json("https://hiplot.cn/ui/basic/qqplot/data.json")$exampleData[[1]]$textarea[[1]])
data <- as.data.frame(data)

# Convert data structure
data[, "Genotype"] <- factor(data[, "Genotype"], levels = unique(data[, "Genotype"]))

# View data
head(data)
  Genotype Cytokine Experiment facet
1       WT 1.312322     Exp_ 1     A
2       WT 2.171466     Exp_ 2     A
3       WT 1.497610     Exp_ 3     A
4       WT 1.088861     Exp_ 4     A
5       WT 1.270528     Exp_ 5     A
6       WT 3.012708     Exp_ 6     A

Visualization

# QQ Plot
p <- plot_qqline(data = data, ycol = Cytokine, group = Genotype,
                 symsize = 2, symthick = 0.5, s_alpha = 1) +
  ggtitle("QQplot without facet") +
  xlab("theoretical") + ylab("sample") + 
  guides(fill = guide_legend(title = "Genotype")) +
  scale_color_manual(values = c("#E69F00","#4DB1DC")) +
  theme(text = element_text(family = "Arial"),
        plot.title = element_text(size = 12,hjust = 0.5),
        axis.title = element_text(size = 12),
        axis.text = element_text(size = 10),
        axis.text.x = element_text(angle = 0, hjust = 0.5,vjust = 1),
        legend.position = "right",
        legend.direction = "vertical",
        legend.title = element_text(size = 10),
        legend.text = element_text(size = 10))

p
FigureΒ 1: QQ Plot