avPlots

0th

Percentile

Added-Variable Plots

These functions construct added-variable (also called partial-regression) plots for linear and generalized linear models.

Keywords
hplot, regression
Usage
avPlots(model, terms=~., intercept=FALSE, layout=NULL, ask, main, ...)

avp(...)

avPlot(model, ...)

## S3 method for class 'lm':
avPlot(model, variable,
	id.method = list(abs(residuals(model, type="pearson")), "x"),
	labels, 
	id.n = if(id.method[1]=="identify") Inf else 0,
	id.cex=1, id.col=palette()[1],
	col = palette()[1], col.lines = palette()[2],
	xlab, ylab, pch = 1, lwd = 2, 
	main=paste("Added-Variable Plot:", variable),
	grid=TRUE,
	ellipse=FALSE, ellipse.args=NULL, ...)

## S3 method for class 'glm':
avPlot(model, variable, 
	id.method = list(abs(residuals(model, type="pearson")), "x"),
	labels,
	id.n = if(id.method[1]=="identify") Inf else 0,
	id.cex=1, id.col=palette()[1], 
	col = palette()[1], col.lines = palette()[2],
	xlab, ylab, pch = 1, lwd = 2,  type=c("Wang", "Weisberg"), 
	main=paste("Added-Variable Plot:", variable), grid=TRUE,
	ellipse=FALSE, ellipse.args=NULL, ...)
Arguments
model
model object produced by lm or glm.
terms
A one-sided formula that specifies a subset of the predictors. One added-variable plot is drawn for each term. For example, the specification terms = ~.-X3 would plot against all terms except for X3. If this argument is a q
intercept
Include the intercept in the plots; default is FALSE.
variable
A quoted string giving the name of a regressor in the model matrix for the horizontal axis
layout
If set to a value like c(1, 1) or c(4, 3), the layout of the graph will have this many rows and columns. If not set, the program will select an appropriate layout. If the number of graphs exceed nine, you must select the la
main
The title of the plot; if missing, one will be supplied.
ask
If TRUE, ask the user before drawing the next plot; if FALSE don't ask.
...
avPlots passes these arguments to avPlot. avPlot passes them to plot.
id.method,labels,id.n,id.cex,id.col
Arguments for the labelling of points. The default is id.n=0 for labeling no points. See showLabels for details of these arguments.
col
color for points; the default is the second entry in the current color palette (see palette and par).
col.lines
color for the fitted line.
pch
plotting character for points; default is 1 (a circle, see par).
lwd
line width; default is 2 (see par).
xlab
x-axis label. If omitted a label will be constructed.
ylab
y-axis label. If omitted a label will be constructed.
type
if "Wang" use the method of Wang (1985); if "Weisberg" use the method in the Arc software associated with Cook and Weisberg (1999).
grid
If TRUE, the default, a light-gray background grid is put on the graph.
ellipse
If TRUE, plot a concentration ellipse; default is FALSE.
ellipse.args
Arguments to pass to the link{dataEllipse} function, in the form of a list with named elements; e.g., ellipse.args=list(robust=TRUE)) will cause the ellipse to be plotted using a robust covariance-matrix.
Details

The function intended for direct use is avPlots (for which avp is an abbreviation).

Value

  • These functions are used for their side effect id producing plots, but also invisibly return the coordinates of the plotted points.

References

Cook, R. D. and Weisberg, S. (1999) Applied Regression, Including Computing and Graphics. Wiley. Fox, J. (2008) Applied Regression Analysis and Generalized Linear Models, Second Edition. Sage. Fox, J. and Weisberg, S. (2011) An R Companion to Applied Regression, Second Edition, Sage. Wang, P C. (1985) Adding a variable in generalized linear models. Technometrics 27, 273--276. Weisberg, S. (2014) Applied Linear Regression, Fourth Edition, Wiley.

See Also

residualPlots, crPlots, ceresPlots, link{dataEllipse}

Aliases
  • avPlots
  • avp
  • avPlot
  • avPlot.lm
  • avPlot.glm
Examples
avPlots(lm(prestige~income+education+type, data=Duncan))

avPlots(glm(partic != "not.work" ~ hincome + children, 
  data=Womenlf, family=binomial))
Documentation reproduced from package car, version 2.0-20, License: GPL (>= 2)

Community examples

Looks like there are no examples yet.