ggplot: remove lines at ribbon edges

Question

I am using ggplot to plot time course data (fixation proportions over time to different objects on the screen) and want to use a ribbon to show the SE, but the ribb

Answer 1

Here you go

ggplot(d, aes(Time, y,  fill=Object)) + 
  geom_line(size=2, aes(colour = Object)) + 
  geom_ribbon(aes(ymin=lower, ymax=upper), alpha=.3)

Answer 2

You can remove the border using the colour argument:

ggplot(d, aes(Time, y, color = Object, fill = Object)) +
  geom_line(size = 2) +
  geom_ribbon(aes(ymin = lower, ymax = upper), alpha = .3, colour = NA)

Answer 3

geom_ribbon understands linetype aesthetic. If you want to map linetype to a variable include it in the aes() argument, otherwise, place linetype outside and just give it 0, like so:

ggplot(d, aes(Time, y, color = Object, fill = Object)) +
  geom_line(size = 2) +
  geom_ribbon(aes(ymin = lower, ymax = upper), linetype = 0, alpha = .3)

More info here: http://docs.ggplot2.org/current/geom_ribbon.html

Answer 4

ggplot2's geom_ribbon() now includes an outline.type argument that helps control how the ribbon outlines are displayed.

Outline Type

library(tidyverse)

huron <- tibble(year = 1875:1972, level = as.vector(LakeHuron))

huron %>%
    ggplot(aes(year, level)) +
    geom_ribbon(aes(ymin = level - 1, ymax = level + 1), 
                fill = "grey70", color = "red", 
                outline.type = "lower") +
    geom_line(aes(y = level))

^{Created on 2020-05-28 by the reprex package (v0.3.0)}

Linetype = 0

Alternatively, as suggested we can set linetype = 0 to remove all lines.

library(tidyverse)

huron <- tibble(year = 1875:1972, level = as.vector(LakeHuron))

huron %>%
    ggplot(aes(year, level)) +
    geom_ribbon(aes(ymin = level - 1, ymax = level + 1), 
                fill = "grey70", color = "red", linetype = 0) +
    geom_line(aes(y = level))

^{Created on 2020-05-28 by the reprex package (v0.3.0)}