api2lm (version 0.2)

cooks_plot: Index plot of Cook's distances for lm object

Description

cooks_plot plots the Cook's distances from the cooks.distance function of a fitted lm object.

Usage

cooks_plot(
  model,
  id_n = 3,
  add_reference = TRUE,
  ...,
  text_arglist = list(),
  abline_arglist = list(),
  extendrange_f = 0.08
)

Arguments

model

A fitted model object from the lm function.

id_n

The number of points to identify with labels. The default is 3.

add_reference

A logical value indicating whether a reference line should be added. See details.

...

Additional arguments passed to the plot function.

text_arglist

Additional arguments passed to the text function, which is used to display the points that are identified.

abline_arglist

A named list specifying additional arguments passed to the abline function for the horizontal reference line added to the plot.

extendrange_f

Positive number(s) specifying the fraction by which the range of the residuals should be extended using the extendrange function. If longer than one, f[1] is used on the left and f[2] on the right.

Author

Joshua French

Details

By default, a reference line is plotted at the 0.5 quantile of a \(F_{p, n-p}\) distribution where \(p = \)length(stats::coef(model)) and \(n - p = \)stats::df.residual(model).

The vertical position of the reference line can be customized by setting the h argument of abline_arglist.

See Also

plot, text, abline, cooks.distance

Examples

lmod <- lm(price ~ sqft_living, data = home_sales)
cooks_plot(lmod, id_n = 1)