ggplot example individual + group change plot

change_plot.R

library(tidyverse)

ind_data <- psych::bfi %>% 
  na.omit() %>% 
  filter(education %in% c(2, 4, 5)) %>% 
  select(A1:A5, education) %>% 
  group_by(education) %>% 
  slice(sample(1:n(), 40)) %>% 
  ungroup() %>% 
  rowid_to_column(".id") %>% 
  pivot_longer(A1:A5, names_to = "day", values_to = "score", names_pattern = "A(\\d)") %>% 
  mutate(education = factor(education, levels = c(2, 4, 5), labels = c("low", "med", "high")))

grp_data <- ind_data %>% 
  group_by(education, day) %>% 
  summarize(
    n = n(),
    mean = mean(score), 
    sd = sd(score), 
    lower = mean - qt(.975, n - 1) * sd / sqrt(n),
    upper = mean + qt(.975, n - 1) * sd / sqrt(n)
  ) %>% 
  ungroup()

ind_data %>% 
  ggplot() + 
  theme_classic() +
  # common aesthetics for all geoms
  aes(x = day,
      fill = education) +
  # individual data lines
  geom_line(aes(y = score, color = education, group = .id), alpha = .3,
            position = position_jitter(width = 0)) + # remove position and width for the exact values
  # group summary CI bands
  geom_ribbon(
    aes(y = mean, ymin = lower, ymax = upper, group = education),
    data = grp_data,
    alpha = .2,
    size = 0
  ) +
  # Group summary means
  geom_line(aes(y = mean, color = education, group = education), data = grp_data, size = 1) +
  geom_point(aes(y = mean, color = education, group = education), data = grp_data, size = 2)