[jmgirard]

In the outliers panel of check_model() and plot() for check_outliers(), the Cook's distance contour lines set the y axis, so it grew with the number of observations (easystats/performance#894, #464). For an lm() with 400 observations and residuals from -2.7 to 3.6, the axis went from about -21 to 21. The axis now follows the residuals, and the contour lines are cut at their range. If no line is left in the panel, the subtitle says that all points are inside the contour lines.

The snapshots that show this panel are not re-recorded here, because they already fail on main on my machine (local package versions). They need a re-record in CI:

• check-model-outliers, check-model-panel, check-outliers-default, check-outliers-modern, outliers-plot-low-n, and the default plot.see_check_outliers snapshot: shorter y axis, cut contour lines.

Refs easystats/performance#894

[Copilot]

🟡 Changes recommended

Snapshots need re-recording, and smoother scaling and all-NA subtitle cases remain unresolved.

1 open issue

• Update outlier panel snapshots for changed contours and axes · New

What changed in this PR

This PR keeps the outliers panel y-axis bounded by standardized residuals instead of Cook’s distance contours.

Changes:

• Clips contours and adjusts labels/subtitles.
• Preserves residual scaling when dots are hidden.
• Adds regression tests and updates NEWS/version metadata.

File	Summary
R/​plot.check_outliers.dots.R	Implements contour clipping and residual-based scaling.
tests/​testthat/​test-check_outliers_y_axis.R	Tests axes, contours, labels, subtitles, and sampling.
tests/​testthat/​test-check_model_show_smooth.R	Updates contour expectations.
NEWS.md	Documents the behavior change.
DESCRIPTION	Bumps the package version.

_{Review effort: Lite}

[jmgirard]

#487 (review)

• R/plot.check_outliers.dots.R:167 (snapshots): not changed. These snapshots already fail on main on my machine because of local package versions, so they need a re-record in the CI environment.
• Smoother scaling: left for a follow-up.
• All-NA subtitle cases: not changed. All-NA contour levels are tested and keep the old subtitle.

[strengejacke]

I have uploaded some updated snapshots for comparison.
However, this PR removes all contour lines from the outliers plot, which should not be the case.
Furthermore, following test fails in tests\testthat\test-check_outliers_y_axis.R:

Error in b$data[[.annotations(p, "GeomText")]]: attempt to select less than one element in get1index

test_that("outliers panel draws only contour lines that reach the residuals", {
  m <- lm(y ~ x, data = rbind(d, data.frame(x = 0, y = 6.8)))
  p <- plot(.outliers_check(m))
  expect_length(.annotations(p, "GeomLine"), 1)
  b <- ggplot2::ggplot_build(p)
  label <- b$data[[.annotations(p, "GeomText")]]
  expect_identical(nrow(label), 1L)
  expect_identical(label$x, max(b$data[[1]]$x))
})

[strengejacke]

In summary: Contour lines should not be removed from plots

[jmgirard]

Sorry, we should close this PR without merging. I thought this would help easystats/performance#894, but the LOESS changes fixed that and this isn't necessary.