19.5 Bar plots

# A simple bar plot
ggplot(data=df2, mapping=aes(x=grouping)) + geom_bar()

• Customize:
  • scale_x_discrete is used to handle x-axis title and labels
  • coord_flip swaps the x and y axis

# Save the plot in the object "p"
pbar <- ggplot(data=df2, mapping=aes(x=grouping, fill=grouping)) + 
  geom_bar()

# Change x axis label with scale_x_discrete and change order of the bars:
p2 <- pbar + scale_x_discrete(name="counts of yes / no", limits=c("yes", "no"))

# Swapping x and y axis with coord_flip():
p3 <- p2 + coord_flip()

# Change fill
p4 <- p3 + scale_fill_manual(values=c("yellow", "cyan"))

# Show intermediary and final plots
pbar

p2

p3

p4