Quantile-Quantile plot.

ggqqplot(
  data,
  x,
  combine = FALSE,
  merge = FALSE,
  color = "black",
  palette = NULL,
  size = NULL,
  shape = NULL,
  add = c("qqline", "none"),
  add.params = list(linetype = "solid"),
  conf.int = TRUE,
  conf.int.level = 0.95,
  title = NULL,
  xlab = NULL,
  ylab = NULL,
  facet.by = NULL,
  panel.labs = NULL,
  short.panel.labs = TRUE,
  ggtheme = theme_pubr(),
  ...
)

Arguments

data

a data frame

x

variable to be drawn.

combine

logical value. Default is FALSE. Used only when y is a vector containing multiple variables to plot. If TRUE, create a multi-panel plot by combining the plot of y variables.

merge

logical or character value. Default is FALSE. Used only when y is a vector containing multiple variables to plot. If TRUE, merge multiple y variables in the same plotting area. Allowed values include also "asis" (TRUE) and "flip". If merge = "flip", then y variables are used as x tick labels and the x variable is used as grouping variable.

color

point color.

palette

the color palette to be used for coloring or filling by groups. Allowed values include "grey" for grey color palettes; brewer palettes e.g. "RdBu", "Blues", ...; or custom color palette e.g. c("blue", "red"); and scientific journal palettes from ggsci R package, e.g.: "npg", "aaas", "lancet", "jco", "ucscgb", "uchicago", "simpsons" and "rickandmorty".

size

point size.

shape

point shape.

add

character vector. Allowed values are one of "none" and "qqline" (for adding qqline).

add.params

parameters (color, size, linetype) for the argument 'add'; e.g.: add.params = list(color = "red").

conf.int

logical value. If TRUE, confidence interval is added.

conf.int.level

the confidence level. Default value is 0.95.

title

plot main title.

xlab

character vector specifying x axis labels. Use xlab = FALSE to hide xlab.

ylab

character vector specifying y axis labels. Use ylab = FALSE to hide ylab.

facet.by

character vector, of length 1 or 2, specifying grouping variables for faceting the plot into multiple panels. Should be in the data.

panel.labs

a list of one or two character vectors to modify facet panel labels. For example, panel.labs = list(sex = c("Male", "Female")) specifies the labels for the "sex" variable. For two grouping variables, you can use for example panel.labs = list(sex = c("Male", "Female"), rx = c("Obs", "Lev", "Lev2") ).

short.panel.labs

logical value. Default is TRUE. If TRUE, create short labels for panels by omitting variable names; in other words panels will be labelled only by variable grouping levels.

ggtheme

function, ggplot2 theme name. Default value is theme_pubr(). Allowed values include ggplot2 official themes: theme_gray(), theme_bw(), theme_minimal(), theme_classic(), theme_void(), ....

...

other arguments to be passed to ggpar.

Details

The plot can be easily customized using the function ggpar(). Read ?ggpar for changing:

  • main title and axis labels: main, xlab, ylab

  • axis limits: xlim, ylim (e.g.: ylim = c(0, 30))

  • axis scales: xscale, yscale (e.g.: yscale = "log2")

  • color palettes: palette = "Dark2" or palette = c("gray", "blue", "red")

  • legend title, labels and position: legend = "right"

  • plot orientation : orientation = c("vertical", "horizontal", "reverse")

See also

Examples

# Create some data format set.seed(1234) wdata = data.frame( sex = factor(rep(c("F", "M"), each=200)), weight = c(rnorm(200, 55), rnorm(200, 58))) head(wdata, 4)
#> sex weight #> 1 F 53.79293 #> 2 F 55.27743 #> 3 F 56.08444 #> 4 F 52.65430
# Basic QQ plot ggqqplot(wdata, x = "weight")
# Change colors and shape by groups ("sex") # Use custom palette ggqqplot(wdata, x = "weight", color = "sex", palette = c("#00AFBB", "#E7B800"))