geom_area with negative y not working in ggplot2 3.2.0

[vadimus202]

In ggplot2 3.1.1 the area under the curve handles negative values

library(ggplot2)

set.seed(115)

ggplot(
    data.frame(
        x = 1:100,
        y = cumsum(rnorm(n = 100, mean = 0, sd = 3))
    ),
    aes(x, y)) +
    geom_area(fill = "pink", alpha = 0.5) +
    geom_path()

In ggplot2 3.2.0 something goes wrong:

library(ggplot2)

set.seed(115)

ggplot(
    data.frame(
        x = 1:100,
        y = cumsum(rnorm(n = 100, mean = 0, sd = 3))
    ),
    aes(x, y)) +
    geom_area(fill = "pink", alpha = 0.5) +
    geom_path()

[yutannihilation]

A simpler version of code (Sorry, I can't render the reprex right now...). Not sure what's happening here, but it seems something went wrong...

library(ggplot2)

d <- data.frame(
  x = 1:6,
  y = c(1, 2, 2, 1, 0, -1)
)

ggplot(d, aes(x, y)) +
  geom_area(fill = "pink", alpha = 0.5) +
  geom_point()

ggplot(d, aes(x, y - 1)) +
  geom_area(fill = "pink", alpha = 0.5) +
  geom_point()

[clauswilke]

Rendered reprex below.

@thomasp85 Is this somehow related to the rewritten polygon rendering code? We may have to consider a hotfix release, since this is a serious regression.

library(ggplot2)

d <- data.frame(
  x = 1:6,
  y = c(1, 2, 2, 1, 0, -1)
)

ggplot(d, aes(x, y)) +
  geom_area(fill = "pink", alpha = 0.5) +
  geom_point()

ggplot(d, aes(x, y - 1)) +
  geom_area(fill = "pink", alpha = 0.5) +
  geom_point()

^{Created on 2019-07-03 by the reprex package (v0.3.0)}

[thomasp85]

I’ll look into it.

[thomasp85]

This is due to GeomArea/GeomRibbon now sorting their data in setup_data instead of in draw_panel. PositionStack changes the ordering of the data and that is no longer resolved as it comes after setup_data.

There are two ways around this.

1. Make sure PositionStack doesn't change the ordering of data
2. Make a secondary sort in draw_panel()

I generally prefer 1) as it is how I think positions should behave (i.e. not fiddle with data ordering), but it may have unforeseen consequences 🤷‍♂️

I agree this should be fixed in a hot fix (and we really should have some tests to catch this) cc @hadley

[hadley]

1. sounds reasonable. And it shouldn't be too bad to do a patch release for this issue. Do we want to wait a week in case any other problems come in?

[thomasp85]

Let's wait a week before we start release process

[karawoo]

If I recall correctly, the ordering in PositionStack exists to fix my first ever bug report (#1552) 🙂. So it is there for a reason, but it's possible that reason has been obviated by other changes since. I can try to look into it this weekend.

[karawoo]

I've opened a PR that will address this, but in the meantime geom_ribbon() still works:

library(ggplot2)

set.seed(115)

ggplot(
  data.frame(
    x = 1:100,
    y = cumsum(rnorm(n = 100, mean = 0, sd = 3))
  ),
  aes(x, y)) +
  geom_ribbon(aes(ymax = y, ymin = 0), fill = "pink", alpha = 0.5) +
  geom_path()

^{Created on 2019-07-17 by the reprex package (v0.3.0)}

[yutannihilation]

@thomasp85 @hadley

Let's wait a week before we start release process

Some weeks have passed. Do we start the process? While this issue should be hot-fixed, this might not be as serious as we thought at first in terms of the number of users affected, considering the fact there's no other issues filed than this one. So, if you are very busy (sorry, I don't think I can review #3401...), I think it's okay not to hurry so much.

But, I'm a bit worrying about that the CRAN check is all red probably due to #3394 (, which seems already fixed by @paleolimbot). Do you get any serious warnings about this from CRAN people?

https://cran.rstudio.com/web/checks/check_results_ggplot2.html

[thomasp85]

I’m currently on vacation (this week and next). I’ll begin release once I’m back