eda_sym: Symmetry QQ plot

In mgimond/tukeyedar: Tukey Inspired Exploratory Data Analysis Functions

Symmetry QQ plot

Description

eda_sym Generates a symmetry QQ plot.

Usage

eda_sym(
  x,
  p = 1L,
  tukey = FALSE,
  q.type = 5,
  plot = TRUE,
  show.par = TRUE,
  grey = 0.6,
  pch = 21,
  p.col = "grey50",
  p.fill = "grey80",
  size = 0.8,
  alpha = 0.8,
  q = TRUE,
  tails = FALSE,
  inner = 0.75,
  tail.pch = 21,
  tail.p.col = "grey70",
  tail.p.fill = NULL,
  xlab = NULL,
  ylab = NULL,
  title = NULL,
  t.size = 1.2,
  ...
)

Arguments

x	Vector of sample
p	Power transformation to apply to x.
tukey	Boolean determining if a Tukey transformation should be adopted (FALSE adopts a Box-Cox transformation).
q.type	An integer between 1 and 9 selecting one of the nine quantile algorithms used to generate inner shaded region. (See quantiletile function).
plot	Boolean determining if plot should be generated.
show.par	Boolean determining if power parameter should be displayed.
grey	Grey level to apply to plot elements (0 to 1 with 1 = black).
pch	Point symbol type.
p.col	Color for point symbol.
p.fill	Point fill color passed to bg (Only used for pch ranging from 21-25).
size	Point size (0-1)
alpha	Point transparency (0 = transparent, 1 = opaque). Only applicable if rgb() is not used to define point colors.
q	Boolean determining if inner data region should be shaded.
tails	Boolean determining if points outside of the inner region should be symbolized differently. Tail-end points are symbolized via the tail.pch, tail.p.col and tail.p.fill arguments.
inner	Fraction of the data considered as "mid values". Defaults to 75\ which of the tail-end points are to be symbolized differently, tails.
tail.pch	Tail-end point symbol type (See tails).
tail.p.col	Tail-end color for point symbol (See tails).
tail.p.fill	Tail-end point fill color passed to bg (Only used for tail.pch ranging from 21-25).
xlab	X label for output plot. Ignored if x is a dataframe.
ylab	Y label for output plot. Ignored if x is a dataframe.
title	Title to add to plot.
t.size	Title size.
...	Not used

Details

Generates a symmetry quantile plot that compares the lower half of the sorted data to its upper half. If the distribution is perfectly symmetrical, the points will fall on the line.

Value

Returns a dataframe of upper and lower halves

References

• John M. Chambers, William S. Cleveland, Beat Kleiner, Paul A. Tukey. Graphical Methods for Data Analysis (1983)

• Symmetry quantile plot article

Examples

 singer <- lattice::singer
 tenor1 <- subset(singer, voice.part == "Tenor 1", select = height, drop = TRUE )

 eda_sym(tenor1)

mgimond/tukeyedar documentation built on Feb. 1, 2025, 4:02 a.m.