influencePlot {car} | R Documentation |
Regression Influence Plot
Description
This function creates a “bubble” plot of Studentized residuals by hat values, with the areas of the circles representing the observations proportional to Cook's distances. Vertical reference lines are drawn at twice and three times the average hat value, horizontal reference lines at -2, 0, and 2 on the Studentized-residual scale.
Usage
influencePlot(model, ...)
## S3 method for class 'lm'
influencePlot(model, scale=10,
xlab="Hat-Values", ylab="Studentized Residuals",
labels, id.method = "noteworthy",
id.n = if(id.method[1]=="identify") Inf else 0,
id.cex=1, id.col=palette()[1], ...)
Arguments
model |
a linear or generalized-linear model. |
scale |
a factor to adjust the size of the circles. |
xlab , ylab |
axis labels. |
labels , id.method , id.n , id.cex , id.col |
settings for labelling
points; see |
... |
arguments to pass to the |
Value
If points are identified, returns a data frame with the hat values, Studentized residuals and Cook's distance of the identified points. If no points are identified, nothing is returned. This function is primarily used for its side-effect of drawing a plot.
Author(s)
John Fox jfox@mcmaster.ca, minor changes by S. Weisberg sandy@umn.edu
References
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.
See Also
cooks.distance
, rstudent
,
hatvalues
, showLabels
Examples
influencePlot(lm(prestige ~ income + education, data=Duncan))