plot.visreg: Visualization of regression functions

In pbreheny/visreg: Visualization of Regression Models

Visualization of regression functions

Description

A function for visualizing regression models quickly and easily. Default plots contain a confidence band, prediction line, and partial residuals. Factors, transformations, conditioning, interactions, and a variety of other options are supported. The 'plot.visreg()' function accepts a 'visreg' or 'visregList' object as calculated by [visreg()] and creates the plot.

Usage

## S3 method for class 'visreg'
plot(
  x,
  overlay = FALSE,
  print.cond = FALSE,
  whitespace = 0.2,
  partial = identical(x$meta$trans, I),
  band = TRUE,
  rug = ifelse(partial, 0, 2),
  strip.names = is.numeric(x$fit[, x$meta$by]),
  legend = TRUE,
  top = c("line", "points"),
  gg = FALSE,
  line.par = NULL,
  fill.par = NULL,
  points.par = NULL,
  ...
)

Arguments

x	A 'visreg' or 'visregList' object; see [visreg()].
overlay	By default, when 'by' is specified, separate panels are used to display each cross-section. If 'overlay=TRUE', these cross-sections are overlaid on top of each other in a single plot.
print.cond	If 'print.cond=TRUE', the explanatory variable values conditioned on in a conditional plot are printed to the console (default: 'FALSE'). If 'print.cond=TRUE' and 'type="contrast"', the conditions will still be printed, but they have no bearing on the plot unless interactions are present.
whitespace	When 'xvar' is a factor, 'whitespace' determines the amount of space in between factors on the x-axis. Default is 0.2, meaning that 20 percent of the horizontal axis is whitespace.
partial	If 'partial=TRUE' (the default), partial residuals are shown on the plot.
band	If 'band=TRUE' (the default), confidence bands are shown on the plot.
rug	By default, partial residuals are plotted. Alternatively, a [rug()] may be plotted along the horizontal axis instead. Setting 'rug=TRUE' turns off partial residuals by default; if one wants both to be plotted, both 'rug=TRUE' and 'partial=TRUE' need to be specified. Two types of rug plots are available. If 'rug=1' or 'rug=TRUE', then a basic rug is drawn on the bottom. If rug=2, then separate rugs are drawn on the top for observations with positive residuals and on the bottom for observations with negative residuals. Such plots are particularly useful in logistic regression (see examples).
strip.names	When 'by=TRUE', 'strip.names=TRUE' adds the name of the 'by' variable to the strip at the top of each panel. Default is 'FALSE' for factors and 'TRUE' for numeric 'by' variables. 'strip.names' can also be a character vector, in which case it replaces the strip names altogether with values chosen by the user.
legend	For overlay plots, ('overlay=TRUE'), should visreg create a legend? If 'legend=TRUE' (the default), a legend is placed in the top margin.
top	By default, the fitted line is plotted on top of the partial residuals; usually this is preferable, but it does run the risk of obscuring certain residuals. To change this behavior and plot the partial residuals on top, specify ‘top=’points''.
gg	By default ('gg=FALSE'), 'visreg' will use the **lattice** package to render the plot if multiple panels are required. If 'gg=TRUE', it will use the **ggplot2** package instead, provided that it is installed.
line.par	List of parameters (see [par()]) to pass to 'lines(...)' or [ggplot2::geom_line()] when lines are plotted.
fill.par	List of parameters (see [par()]) to pass to 'polygon(...)' or [ggplot2::geom_polygon()] when shaded confidence regions are plotted.
points.par	List of parameters ([par()]) to pass to 'points(...)' or [ggplot2::geom_point()] when partial residuals are plotted.
...	Graphical parameters can be passed to the function to customize the plots. If 'by=TRUE', lattice parameters can be passed, such as 'layout' (see examples below).

Author(s)

Patrick Breheny and Woodrow Burchett

References

Breheny P and Burchett W. (2017) Visualization of regression models using visreg. *R Journal*, **9**: 56-71. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.32614/RJ-2017-046")}

See Also

https://pbreheny.github.io/visreg/options.html, [visreg()], [visreg2d()]

Examples

fit <- lm(Ozone ~ Solar.R + Wind + Temp,data=airquality)
visreg(fit, "Wind", line=list(col="red"), points=list(cex=1, pch=1))

## Changing appearance
visreg(fit, "Wind", line=list(col="red"), points=list(cex=1, pch=1))

## See ?visreg and https://pbreheny.github.io/visreg for more examples

pbreheny/visreg documentation built on June 4, 2024, 1:21 a.m.