Adding Text to Plots

# Load Packages -----------------------------------------------------------

library(tidyverse)

# Import Data -------------------------------------------------------------

penguins <- read_csv("penguins.csv")

# Adding Text to Plots ---------------------------------------------------------

# Text is just another geom. 
# We can use geom_text() to add labels to our figures.

ggplot(data = penguin_bill_length_by_island,
       mapping = aes(x = island,
                     y = mean_bill_length,
                     fill = island,
                     label = mean_bill_length)) +
  geom_col() +
  geom_text()

# Those text labels are too long!
# Let's create a new variable to use for plotting.
# We're using the number() function from the scales package 
# to make this variable

library(scales)

penguin_bill_length_by_island_v2 <- penguin_bill_length_by_island |> 
  mutate(mean_bill_length_one_digit = number(mean_bill_length, accuracy = 0.1))

# Now let's plot using our new data frame

ggplot(data = penguin_bill_length_by_island_v2,
       mapping = aes(x = island,
                     y = mean_bill_length,
                     fill = island,
                     label = mean_bill_length_one_digit)) +
  geom_col() +
  geom_text()

# Note that we use mean_bill_length_one_digit for the label aesthetic property
# and mean_bill_length for y. 
# If you use mean_bill_length_one_digit for both, your graph will
# look different.

ggplot(data = penguin_bill_length_by_island_v2,
       mapping = aes(x = island,
                     y = mean_bill_length_one_digit,
                     fill = island,
                     label = mean_bill_length_one_digit)) +
  geom_col() +
  geom_text()

# We can use the hjust and vjust arguments to horizontally and vertically 
# adjust text.

# vjust = 0 puts the labels on the outer edge of the bars.

ggplot(data = penguin_bill_length_by_island_v2,
       mapping = aes(x = island,
                     y = mean_bill_length,
                     fill = island,
                     label = mean_bill_length_one_digit)) +
  geom_col() +
  geom_text(vjust = 0)

# vjust = 1 puts the labels at the inner edge of the bars.

ggplot(data = penguin_bill_length_by_island_v2,
       mapping = aes(x = island,
                     y = mean_bill_length,
                     fill = island,
                     label = mean_bill_length_one_digit)) +
  geom_col() +
  geom_text(vjust = 1)

# I often do something like vjust = 1.5 to give a bit more padding. 

ggplot(data = penguin_bill_length_by_island_v2,
       mapping = aes(x = island,
                     y = mean_bill_length,
                     fill = island,
                     label = mean_bill_length_one_digit)) +
  geom_col() +
  geom_text(vjust = 1.5)

# We can adjust the color of the text using the color argument. 
# We're putting it outside of the aes() because we are setting it 
# for the whole layer.

ggplot(data = penguin_bill_length_by_island_v2,
       mapping = aes(x = island,
                     y = mean_bill_length,
                     fill = island,
                     label = mean_bill_length_one_digit)) +
  geom_col() +
  geom_text(vjust = 1.5,
            color = "white")

# geom_label() is nearly identical but it adds a background. 
# With geom_label() the color argument determines the text and border color 
# while the fill is the background color.

ggplot(data = penguin_bill_length_by_island_v2,
       mapping = aes(x = island,
                     y = mean_bill_length,
                     fill = island,
                     label = mean_bill_length_one_digit)) +
  geom_col() +
  geom_label(vjust = 1.5,
             color = "white",
             fill = "black")