I’m trying to visualise ordinal data with the following structure:

library(ggdist)
library(ggplot2)
library(dplyr)

data(long_data)

srss_question1 <- long_data %>%
  filter(type == "1") %>%
  dplyr::select(id, day, response)

head(srss_question1)
# A tibble: 6 × 3
     id day   response
  <dbl> <fct>    <dbl>
1     1 day7         5
2     1 day2         4
3     1 day0         3
4     2 day7         5
5     2 day2         5
6     2 day0         6

Code to plot figure without colour that works as intended:

srss_question1 %>%
  ggplot(aes(y = response, x = day)) +
  stat_slab(
    data = filter(srss_question1, day == "day7"),
    density = "histogram",
    breaks = breaks_fixed(width = 0.5),
    align = "center",
    position = position_nudge(x = 0),
    side = "right"
  ) +
  stat_slab(
    data = filter(srss_question1, day == "day2"),
    density = "histogram",
    breaks = breaks_fixed(width = 0.5),
    align = "center",
    position = position_nudge(x = 0),
    side = "right"
  ) +
  stat_slab(
    data = filter(srss_question1, day == "day0"),
    density = "histogram",
    breaks = breaks_fixed(width = 0.5),
    align = "center",
    position = position_nudge(x = 0),
    side = "right",
  ) +
  geom_line(
    aes(group = id),
    size = 0.25,
    position = position_jitter(h = 0.05, w = 0.05),
    alpha = 0.25
  ) +
  scale_y_continuous(limits = c(-0.25, 7.5), breaks = 0:10) +
  labs(x = "Day", y = "Question 1 Responses") +
  theme_bw()

Which produces this figure:
Figure Gray

I’d like to see if mapping the Viridis colour palette to this figure helps with the visualisation and have coded it as such here:

srss_question1 %>%
  ggplot(aes(x = day, y = response, fill = factor(response))) +
    stat_slab(
    data = filter(srss_question1, day == "day7"),
    density = "histogram",
    breaks = breaks_fixed(width = 0.5),
    align = "center",
    side = "right",
    position = position_nudge(x = 0)
  ) +      
    stat_slab(
    data = filter(srss_question1, day == "day2"),
    density = "histogram",
    breaks = breaks_fixed(width = 0.5),
    align = "center",
    side = "right",
    position = position_nudge(x = 0)
  ) +
    stat_slab(
    data = filter(srss_question1, day == "day0"),
    density = "histogram",
    breaks = breaks_fixed(width = 0.5),
    align = "center",
    side = "right",
    position = position_nudge(x = 0)
  ) +
    geom_line(
    aes(group = id),
    linewidth = 0.25,
    position = position_jitter(h = 0.05, w = 0.05),
    alpha = 0.25
  ) +
  scale_fill_viridis_d(option = "D", direction = 1) +
  scale_y_continuous(limits = c(-0.25, 7.5), breaks = 0:10) +
  labs(x = "Day", y = "Question 1 Responses") +
  theme_bw()

But this removes the bars from the figure like here:
Figure colour

Why do my stat_slab bars disappear when mapping the colour palette to the figure? Any insights on how to fix the code much appreciated 🙂

Please let me know if more information is needed.