index_plot_lm {api2lm}

Index plot of statistics from of an lm object

Description

index_plot_lm creates an index plot of statistcs from an lm object.

Usage

index_plot_lm(
  model,
  stat,
  id_n = 3,
  add_reference = FALSE,
  ...,
  text_arglist = list(),
  abline_arglist = list(),
  extendrange_f = 0.08
)

Arguments

model

A fitted model object from the lm function.

stat

A function that can be applied to an lm object and returns a vector of observations for each observation used to fit the model.

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. The default is TRUE.

...

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(s)

Joshua French

See Also

plot, text, lm, rstudent, hatvalues, cooks.distance

Examples

lmod <- lm(Petal.Length ~ Sepal.Length + Species,
           data = iris)
# outlier plot
# number of observations
n <- stats::nobs(lmod)
# loo residual degrees of freedom
rdf <- stats::df.residual(lmod) - 1

h <- c(-1, 1) * stats::qt(0.05/(2 * n), df = rdf)
index_plot_lm(lmod, stat = stats::rstudent,
              abline_arglist = list(h = h))

# leverage plot
index_plot_lm(lmod, stat = stats::hatvalues, id_n = 1)
# Cook's distance
index_plot_lm(lmod, stat = stats::cooks.distance,
              id_n = 3)