eda_theopan: Multi-panel theoretical QQ plots

In mgimond/tukeyedar: Tukey Inspired Exploratory Data Analysis Functions

Multi-panel theoretical QQ plots

Description

eda_theopan generates a multi-panel theoretical QQ plot for a continuous variable conditioned on a grouping variable.

Usage

eda_theopan(
  dat,
  x,
  fac,
  p = 1L,
  tukey = FALSE,
  q.type = 5,
  dist = "norm",
  dist.l = list(),
  ylim = NULL,
  resid = FALSE,
  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 = 0.7,
  alpha = 0.8,
  q = FALSE,
  tails = FALSE,
  med = FALSE,
  inner = 0.75,
  iqr = TRUE,
  title = FALSE,
  xlab = NULL,
  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 nine quantile algorithms. (See eda_fval for a list of quantile algorithms).
dist	Theoretical distribution to use. Defaults to Normal distribution.
dist.l	List of parameters passed to the distribution quantile function.
ylim	Y axes limits.
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.
iqr	Boolean determining if an IQR line should be fitted to the points.
title	Title to display. If set to TRUE, defaults to theoretical distribution type. If set to FALSE, omits title from output. Custom title can also be passed to this argument.
xlab	X-axis label.
ylab	Y-axis label.
...	Not used

Details

The function will generate a multi-panel theoretical QQ plot. Currently, only the Normal QQ plot (dist="norm"), exponential QQ plot (dist="exp"), uniform QQ plot (dist="unif"), gamma QQ plot (dist="gamma"), chi-squared QQ plot (dist="chisq"), and the Weibull QQ plot (dist="weibull") are currently supported. By default, the Normal QQ plot maps the unit Normal quantiles to the x-axis (i.e. centered on a mean of 0 and standard deviation of 1 unit).

Value

Returns a list with the following components:

• data: List with input x and y values for each group. May be interpolated to smallest quantile batch if batch sizes don't match. Values will reflect power transformation defined in p

.

References

• William S. Cleveland. Visualizing data. (1993)

See Also

• eda_fval for computing f-values

• eda_theo for a single theoretical QQ plot

Examples

# Default output
singer <- lattice::singer
eda_theopan(singer, height, voice.part)

# Split into two rows
eda_theopan(singer, height, voice.part, nrow = 2, title = TRUE)

# Compare to a uniform distribution
eda_theopan(singer, height, voice.part, nrow = 2, dist = "unif")

# A uniform QQ plot is analogous to a Q(f) plot
eda_theopan(singer, height, voice.part, nrow = 2, dist = "unif",
              iqr = FALSE, xlab = "f-value")

# Normal QQ plots of Waterville daily averages. Mean monthly values are
# subtracted from the data to recenter all batches around 0.  Color and point
# symbols are used to emphasize the inner core of the data (here set to the
# inner 80% of values)
wat <- tukeyedar::wat05
wat$month <- factor(format(wat$date,"%b"), levels = month.abb)
eda_theopan(wat,avg, month, resid = TRUE, nrow = 3, inner = 0.8 ,
                    tails = TRUE, tail.pch = 3, p.fill = "coral")

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