I would appreciate any help on how to add the error bars to the following plot. I have changed the values of “width” or “position_dodge” but it didn’t work.

library(ggplot2)
library(dplyr)
library(tidyr)
library(ggh4x)

df <- expand.grid(  
  group = c("Children", "Teenagers"),  
  task = c("A", "B", "C"),  
  hemisphere = c("Left", "Right"),  
  region = c("Frontal", "Motor"),  
  frequency = c("Alpha", "Beta", "Theta")  
)  

df$power <- runif(nrow(df))  # Random power values for demonstration  

avg_power <- df %>%  
  group_by(task, group, frequency) %>%  
  summarize(mean_power_left = mean(power[hemisphere == "Left"]),   
            mean_power_right = mean(power[hemisphere == "Right"]),   
            mean_power_frontal = mean(power[region == "Frontal"]),   
            mean_power_motor = mean(power[region == "Motor"]),   
            .groups = 'drop')  

avg_power_long <- avg_power %>%  
  pivot_longer(cols = starts_with("mean_power"),  
               names_to = "area",   
               names_pattern = "mean_power_(.*)") %>%  
  mutate(area = factor(area, levels = c("left", "right", "frontal", "motor"), 
                       labels = c("Left", "Right", "Frontal", "Motor"))) %>%
  arrange(task, group, frequency, area) %>%
  select(group, task, frequency, area, value) %>%
  rename(power = value)

avg_power_long <- avg_power_long %>%
  mutate(region = case_when(area == c("Left", "Right") ~ "Hemisphere",
                            area == c("Frontal", "Motor") ~ "Area"),
         .before = power)

interaction_plot <- avg_power_long %>% 
  mutate(frequency = factor(frequency, levels = c("Theta", "Alpha", "Beta"))) %>%
  ggplot(aes(x = task, y = power, color = group)) +
  stat_summary(fun = mean, geom = "line", aes(group = group), linewidth = 1.5) + 
  stat_summary(fun.data = mean_cl_boot, geom = "errorbar", width = 0.3, 
               position = position_dodge(0.4)) +
  facet_nested(frequency ~ region + area) +
  labs(title = "",
       x = "Task", y = "Mean EEG Band Power",
       color = "Group") +
  theme_minimal(base_size = 15) +
  theme(strip.text.x = element_text(size = 14),
        strip.placement = "outside")

print(interaction_plot)

I am not sure whether the problem is related to “mean_cl_boot”.