R: QQ Plots

ggqqplot {ggpubr} | R Documentation

## QQ Plots

### Description

Quantile-Quantile plot.

### Usage

    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

`ggpar`

### 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)

    # 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"))

[Package ggpubr version 0.1.6 Index]