A function to display stats::influence()'s sigma value.

ggally_nostic_sigma(
data,
mapping,
...,
lineColor = brew_colors("grey"),
linePosition = attr(data, "broom_glance")\$sigma
)

## Arguments

data, mapping, ..., lineColor parameters supplied to ggally_nostic_line line that is drawn in the background of the plot. Defaults to the overall model's sigma value.

## Value

ggplot2 plot object

## Details

As stated in stats::influence() documentation:

sigma: a vector whose i-th element contains the estimate of the residual standard deviation obtained when the i-th case is dropped from the regression. (The approximations needed for GLMs can result in this being 'NaN'.)

A line is added to display the overall model's sigma value. This gives a baseline for comparison

## See also

stats::influence()

## Examples

# 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_sigma(dt, ggplot2::aes(wt, .sigma)))