quick example of a (not ugly) ggplot bar graph with points for individual subjects and error bars

example_bar_plot.R

# example of bar plot with individual subject points for Anya -04/24/2019
# added error bars - 04/25/2019

library(tidyverse) #will need to install this first (run: install.packages("tidyverse"))


## fake data
data = tibble( # creating a dataframe (aka "tibble") called data
  subject = rep(1:10,times = 2 ), # making a column/vector of subject numbers (1-10) x2
  condition = rep(c("hard", "easy"), each = 10), # making a column/vector of condition names
  response = c(rnorm(10, mean = 5, sd = 1), rnorm(10, mean = 3, sd = 1)) # randomly generating responses from normal distributions with different means
)

## quick and dirty plot for looking at your data in the privacy of your laptop
basic_plot = ggplot(data)+ # essential first piece where you "set the stage"
  # first layer here is going to take the mean of the y values and draw columns with those means as their height
  stat_summary(mapping = aes(x = condition, y = response, fill = condition), geom = 'col', fun.y = 'mean', color = 'black')+
  # second layer will just plot each response value without doing any kind of transformation
  geom_point(mapping = aes(x = condition, y = response, fill = condition), shape = 21, size = 3)

basic_plot # voila, you have a basic plot!

## nicer plot you can put in papers
better_plot = ggplot(data)+ 
  stat_summary(mapping = aes(x = condition, y = response, fill = condition), geom = 'col', fun.y = 'mean', color = 'black')+
  #adding jitter to avoid overplotting
  geom_point(mapping = aes(x = condition, y = response, fill = condition), shape = 21, size = 3, position = position_jitter(width = 0.2, height=0))+
  #adding error bars (standard error)
  stat_summary(mapping = aes(x = condition, y = response), geom = 'errorbar', fun.data = 'mean_se', color = 'black',size = 2, width=0)+
  #after doing the same basic/important stuff as in the plot above, you cn start tweaking the aesthetics
  scale_fill_brewer(palette = "BuGn", name = NULL, breaks = c("easy","hard"), labels = c("Easy", "Hard"))+ # changes the color palette and makes the legend labels nicer
  labs(x = NULL, y = "% BOLD response")+ # changes the y axis label, removes x axis label
  theme_classic(base_size = 20)+ # changes the overall style of the plot
  theme(axis.title.x = element_blank(), axis.text.x = element_blank(), axis.ticks.x = element_blank()) # adjusting further aspects of the plot, removing unneccessary tick marks, etc.

better_plot

#save plot when you're happy with it
ggsave("<filename.pdf>", plot = better_plot)