ggally_nostic_hat: `ggnostic` leverage points

Description

A function to display stats::influence's hat information against a given explanatory variable.

Usage

ggally_nostic_hat(
  data,
  mapping,
  ...,
  linePosition = 2 * sum(eval_data_col(data, mapping$y))/nrow(data),
  lineColor = brew_colors("grey"),
  lineSize = 0.5,
  lineAlpha = 1,
  lineType = 2,
  avgLinePosition = sum(eval_data_col(data, mapping$y))/nrow(data),
  avgLineColor = brew_colors("grey"),
  avgLineSize = lineSize,
  avgLineAlpha = lineAlpha,
  avgLineType = 1
)

Value

ggplot2 plot object

Arguments

data, mapping, ...: supplied directly to ggally_nostic_line
linePosition, lineColor, lineSize, lineAlpha, lineType: parameters supplied to ggplot2::geom_line() for the cutoff line
avgLinePosition, avgLineColor, avgLineSize, avgLineAlpha, avgLineType: parameters supplied to ggplot2::geom_line() for the average line

Details

As stated in stats::influence() documentation:

hat: a vector containing the diagonal of the 'hat' matrix.

The diagonal elements of the 'hat' matrix describe the influence each response value has on the fitted value for that same observation.

A suggested "cutoff" line is added to the plot at a height of 2 * p / n and an expected line at a height of p / n. If either linePosition or avgLinePosition is NULL, the respective line will not be drawn.

Examples

Run this code

# Small function to display plots only if it's interactive
p_ <- GGally::print_if_interactive

dt <- broomify(stats::lm(mpg ~ wt + qsec + am, data = mtcars))
p_(ggally_nostic_hat(dt, ggplot2::aes(wt, .hat)))