# influence.plot

0th

Percentile

##### Regression Influence Plot

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.

Keywords
regression
##### Usage
influence.plot(model, scale = 10, col = c(1, 2), labels = names(rstud), ...)
##### 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.
...
arguments to pass to the plot function.
##### Value

• Returns the indices of identified points.

##### References

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

cookd, rstudent, hatvalues
data(Duncan)
influence.plot(lm(prestige ~ income + education, data=Duncan))