Provide filled counter-part for geom_step

[holgerbrandl]

To visualize discrete state change progressions, it would be great if geom_step could be extended to also provide a filled counter-part (similar to geom_area).

For a discussion ( including some rather tedious workarounds) see https://stackoverflow.com/questions/21887088/generate-a-filled-geom-step

Currently, with geom_area we get

Because of the way geom_area works there are linear interpolations between subsequent points, which are incorrect as they are not reflected in the step-wise nature of the data.

Since the state changes are discrete in nature, geom_step gives a more precise (but visually flawed) picture

Example data:
filled_step_data.csv

Example code:

require(tidyverse)

read_csv("filled_step_data.csv") %>%
      ggplot(aes(timestamp, accu_moves)) +
     # geom_step() +
     geom_area()

[smouksassi]

you might want to look at :
https://adibender.github.io/pammtools/reference/geom_stepribbon.html

ggalt:
https://github.com/hrbrmstr/ggalt/blob/master/R/stat-stepribbon.r

and change it to be like filled areas where the bottom is zero
apply stairstepn only to the y instead of ymax and ymin

[holgerbrandl]

Thanks @smouksassi for the pointer. Indeed

read_csv("~/filled_step_data.csv") %>%
  ggplot(aes(timestamp)) +
  geom_ribbon(aes(ymin = 0, ymax = accu_moves), stat = "stepribbon")

produces a filled geom_step chart (wich has the same shape as geom_step)

[holgerbrandl]

Was it fixed or rejected @thomasp85 ? I still think this would complement ggplot2 in an often-needed manner.

[thomasp85]

It was closed because a solution already exists in an extension. We aim to avoid adding new geoms to ggplot2 if at all possible since the maintenance burden is already quite high as is

[holgerbrandl]

I understand. Thanks for the update.

[jan-glx]

ggalt::GeomStepribbon does not seem to work with position="stack"; that made me wonder if the ability to play Tetris is considered "within the scope of ggplot2"?

[teunbrand]

@jan-glx Having a compatible implementation between ggalt::stat_stepribbon() and position = 'stack' is in scope of {ggalt}, not {ggplot2}.