stat_abline()?

[ASKurz]

Would it be possible to support a function that could take intercept and slope arguments, like geom_abline(), but display the posterior summary in a way like stat_lineribbon()?

[mjskay]

It's an interesting question... in principle yes, though it would have to correctly handle potential correlation between intercept and slope. So it could work for sample-based input that provides both as vectors of draws but would need a consistent way to give a joint distribution of slope and intercept for {distributional} or posterior::rvar input. One possible approach is bringing back the dist aesthetic or making a new one like xydist or joint_dist.

This might also make the most sense as a function that can be used as a data argument or even a stat that outputs values suitable for input to stat_lineribbon() (perhaps combined with a future ggplot2::stat_chain() if/when that appears). Possibly could also have pieces in common with a solution to #140.