Multi-panel pooled values QQ plots — eda

eda_qqpool generates multi-panel pooled values QQ plots for a continuous variable conditioned on a grouping variable. This plot is most frequently used to compare residuals to pooled residuals.

Usage

eda_qqpool(
  dat,
  x,
  fac,
  p = 1L,
  tukey = FALSE,
  q.type = 5,
  resid = TRUE,
  stat = mean,
  show.par = FALSE,
  plot = TRUE,
  grey = 0.6,
  pch = 21,
  nrow = 1,
  p.col = "grey40",
  p.fill = "grey60",
  size = 1,
  text.size = 0.8,
  tail.pch = 21,
  tail.p.col = "grey70",
  tail.p.fill = NULL,
  tic.size = 0.8,
  alpha = 0.8,
  q = FALSE,
  tails = FALSE,
  med = FALSE,
  inner = 0.75,
  title = FALSE,
  ylab = NULL,
  ...
)

Arguments

dat: Data frame.
x: Continuous variable.
fac: Categorical variable.
p: Power transformation to apply to the continuous variable.
tukey: Boolean determining if a Tukey transformation should be adopted (FALSE adopts a Box-Cox transformation).
q.type: An integer between 4 and 9 selecting one of the six quantile algorithms (See eda_fval for a list of quantile algorithms).
resid: Boolean determining if residuals should be plotted. Residuals are computed using the stat parameter.
stat: Statistic to use if residuals are to be computed. Currently mean (default) or median.
show.par: Boolean determining if power transformation should be displayed in the plot.
plot: Boolean determining if plot should be generated.
grey: Grey level to apply to plot elements (0 to 1 with 1 = black).
pch: Point symbol type.
nrow: Define the number of rows for panel layout.
p.col: Color for point symbol.
p.fill: Point fill color passed to bg (Only used for pch ranging from 21-25).
size: Point symbol size (0-1).
text.size: Size for category text above the plot.
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).
tic.size: Size of tic labels (defaults to 0.8).
alpha: Point transparency (0 = transparent, 1 = opaque). Only applicable if rgb() is not used to define point colors.
q: Boolean determining if grey box highlighting the inner region should be displayed.
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.
med: Boolean determining if median lines should be drawn.
inner: Fraction of mid-values to highlight in q or tails. Defaults to the inner 75 percent of values.
title: Title to display. If set to TRUE, defaults to "Pooled residuals QQ plot". If set to FALSE, omits title from output. Custom title can also be passed to this argument.
ylab: Y and X axes labels.
...: Not used

Value

Returns a dataframe with x (or its residuals if resid = TRUE), fac, the f-value (by fac group), and the matching pooled residuals.

Details

The function will generate a multi-panel pooled values QQ plots. The function defaults to a pooled residuals QQ plots which is the most common use for this kind of plot.

References

William S. Cleveland. Visualizing data. (1993)

Examples


# Default output
singer <- lattice::singer
eda_qqpool(singer, height, voice.part, nrow = 2)