Theme Elements for Image Grobs

In conjunction with the ggplot2::theme system, the following element_ functions enable images in non-data components of the plot, e.g. axis text.

• element_cfb_logo(): draws college team logos instead of their names.

• element_cfb_wordmark(): draws college team wordmarks instead of their names.

• element_cfb_headshot(): draws player headshots instead of their ESPN player IDs.

• element_path(): draws images from valid image URLs instead of the URL.

element_cfb_logo(
  alpha = NULL,
  colour = NA,
  hjust = NULL,
  vjust = NULL,
  color = NULL,
  size = 0.5
)

element_cfb_wordmark(
  alpha = NULL,
  colour = NA,
  hjust = NULL,
  vjust = NULL,
  color = NULL,
  size = 0.5
)

element_cfb_headshot(
  alpha = NULL,
  colour = NA,
  hjust = NULL,
  vjust = NULL,
  color = NULL,
  size = 0.5
)

element_path(
  alpha = NULL,
  colour = NA,
  hjust = NULL,
  vjust = NULL,
  color = NULL,
  size = 0.5
)

Arguments

alpha

The alpha channel, i.e. transparency level, as a numerical value between 0 and 1.

colour, color

The image will be colorized with this color. Use the special character "b/w" to set it to black and white. For more information on valid color names in ggplot2 see https://ggplot2.tidyverse.org/articles/ggplot2-specs.html?q=colour#colour-and-fill.

hjust, vjust

The horizontal and vertical adjustment respectively. Must be a numerical value between 0 and 1.

size

The output grob size in cm (!).

Value

An S3 object of class element.

Details

The elements translate CFB team names or players' ESPN IDs into logo images or player headshots, respectively.

See also

geom_cfb_logos(), geom_cfb_wordmarks(), geom_cfb_headshots(), and geom_from_path() for more information on valid team names, player IDs, and other parameters.

Examples

# \donttest{
library(cfbplotR)
library(ggplot2)

team_abbr <- valid_team_names()
# remove conference logos from this example
team_abbr <- team_abbr[1:8]

df <- data.frame(
  random_value = runif(length(team_abbr), 0, 1),
  teams = team_abbr
)

# use logos for x-axis
ggplot(df, aes(x = teams, y = random_value)) +
  geom_col(aes(color = teams, fill = teams), width = 0.5) +
  scale_color_cfb(alt_colors = team_abbr) +
  scale_fill_cfb(alpha = 0.4) +
  theme_minimal() +
  theme(axis.text.x = element_cfb_logo())


# use logos for y-axis
ggplot(df, aes(y = teams, x = random_value)) +
  geom_col(aes(color = teams, fill = teams), width = 0.5) +
  scale_color_cfb(alt_colors = team_abbr) +
  scale_fill_cfb(alpha = 0.4) +
  theme_minimal() +
  theme(axis.text.y = element_cfb_logo())


#############################################################################
# Headshot Examples
#############################################################################
library(cfbplotR)
library(ggplot2)

# Silence an nflreadr message that is irrelevant here
old <- options(nflreadr.cache_warning = FALSE)

dfh <- data.frame(
  random_value = runif(9, 0, 1),
  player_id = c("4361182",
                  "4426385",
                  "4567048",
                  "4372519",
                  "4429013",
                  "4240069",
                  "4360932",
                  "4362874",
                  "4429299")
)

# use headshots for x-axis
ggplot(dfh, aes(x = player_id, y = random_value)) +
  geom_col(width = 0.5) +
  theme_minimal() +
  theme(axis.text.x = element_cfb_headshot())


# use headshots for y-axis
ggplot(dfh, aes(y = player_id, x = random_value)) +
  geom_col(width = 0.5) +
  theme_minimal() +
  theme(axis.text.y = element_cfb_headshot())

#############################################################################
# Wordmarks and other Images
#############################################################################

library(ggplot2)

df <- dplyr::mutate(mtcars,
  team = sample(c("Utah", "Arizona State", "Oregon", "UCLA"), nrow(mtcars), TRUE),
  player = sample(
  c("4361182", "4426385", "4567048", "4429013"),
  nrow(mtcars),
  TRUE
  )
)

ggplot(df, aes(x = mpg, y = disp)) +
  geom_point() +
  facet_wrap(vars(team)) +
  labs(
    title = tools::toTitleCase("These are random teams and data"),
    subtitle = "I just want to show how the cfbplotR theme elements work",
    caption = "https://raw.githubusercontent.com/sportsdataverse/sportsdataverse-web/master/public/images/logo.png"
  ) +
  theme_minimal() +
  theme(
    plot.title.position = "plot",
    plot.title = element_text(face = "bold"),
    axis.title = element_blank(),
    # make wordmarks of team abbreviations
    strip.text = element_cfb_wordmark(size = 1),
    # load image from url in caption
    plot.caption = element_path(hjust = 1, size = 0.4)
  )

# }