influence.plot {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

influence.plot(model, ...)

## S3 method for class 'lm':
influence.plot(model, scale = 10, col = c(1, 2), labels = names(rstud), 
  identify.cex=par("cex"), identify.col=par("col"), ...)

Arguments

model a linear or generalized-linear model.
scale a factor to adjust the size of the circles.
col colors for plotting points that do not and do have noteworthy Cook's distances.
labels if FALSE do not identify points interactively with the mouse; otherwise a vector of observation labels.
identify.cex, identify.col aguments to be passed to identify.
... arguments to pass to the plot function.

Value

Returns the indices of identified points.

Author(s)

John Fox jfox@mcmaster.ca

References

J. Fox (2002) An R and S-PLUS Companion to Applied Regression. Sage.

See Also

cookd, rstudent, hatvalues

Examples

    ## Not run: 
    influence.plot(lm(prestige ~ income + education, data=Duncan))
    
## End(Not run)

[Package car version 1.1-0 Index]