Goal Contribution Matrix (J.League: 2018 Season)

goal_contribution_matrix_jleague_2018.r

pacman::p_load(tidyverse, polite, scales, ggimage, 
               rvest, glue, extrafont, ggrepel, magick)
loadfonts()

url <- "https://www.transfermarkt.com/j1-league/startseite/wettbewerb/JAP1/plus/?saison_id=2017"

session <- bow(url)

team_links <- scrape(session) %>% 
  html_nodes("#yw1 > table > tbody > tr > td.zentriert.no-border-rechts > a") %>% 
  html_attr("href")

team_links_df <- team_links %>% 
  enframe(name = NULL) %>% 
  separate(value, c(NA, "team_name", NA, NA, "team_num", NA, NA), sep = "/") %>% 
  mutate(link = glue("https://www.transfermarkt.com/{team_name}/leistungsdaten/verein/{team_num}/reldata/JAP1%262017/plus/1"))
  
# tategaki function for vertical axis-text
tategaki_alt <- function(x){
  x <- stringr::str_replace_all(x, "ー", "丨")
  stringr::str_wrap(x, width = 1)
}

# add_logo function for adding logo via magick package
add_logo <- function(plot_path, logo_path, logo_position, logo_scale = 10){

    # Requires magick R Package https://github.com/ropensci/magick

    # Useful error message for logo position
    if (!logo_position %in% c("top right", "top left", "bottom right", "bottom left")) {
        stop("Error Message: Uh oh! Logo Position not recognized\n  Try: logo_positon = 'top left', 'top right', 'bottom left', or 'bottom right'")
    }

    # read in raw images
    plot <- magick::image_read(plot_path)
    logo_raw <- magick::image_read(logo_path)

    # get dimensions of plot for scaling
    plot_height <- magick::image_info(plot)$height
    plot_width <- magick::image_info(plot)$width

    # default scale to 1/10th width of plot
    # Can change with logo_scale
    logo <- magick::image_scale(logo_raw, as.character(plot_width/logo_scale))

    # Get width of logo
    logo_width <- magick::image_info(logo)$width
    logo_height <- magick::image_info(logo)$height

    # Set position of logo
    # Position starts at 0,0 at top left
    # Using 0.01 for 1% - aesthetic padding

    if (logo_position == "top right") {
        x_pos = plot_width - logo_width - 0.01 * plot_width
        y_pos = 0.01 * plot_height
    } else if (logo_position == "top left") {
        x_pos = 0.01 * plot_width
        y_pos = 0.01 * plot_height
    } else if (logo_position == "bottom right") {
        x_pos = plot_width - logo_width - 0.01 * plot_width
        y_pos = plot_height - logo_height - 0.01 * plot_height
    } else if (logo_position == "bottom left") {
        x_pos = 0.01 * plot_width
        y_pos = plot_height - logo_height - 0.01 * plot_height
    }

    # Compose the actual overlay
    magick::image_composite(plot, logo, offset = paste0("+", x_pos, "+", y_pos))

}

# BIG FUNCTION

jleague_stats_info <- function(link) {
  
  session <- bow(link)
  
  player_name_info <- scrape(session) %>% 
    html_nodes("#yw1 .bilderrahmen-fixed") %>% 
  html_attr("title") 

  num_goals_info <- scrape(session) %>% 
    html_nodes("td:nth-child(7)") %>% 
    html_text()

  num_assists_info <- scrape(session) %>% 
    html_nodes("td:nth-child(8)") %>% 
    html_text()
  
  resultados <- list(player_name_info, num_goals_info, num_assists_info)
  col_names <- c("name", "goals", "assists") 
  
  jleague_stats <- resultados %>% 
    reduce(cbind) %>% 
    as_tibble() %>% 
    set_names(col_names)
  
}

# ALL 18 TEAMS AT ONCE, WILL TAKE A WHILE:
# You can also split this up to do every 3-4 teams and then `reduce(rbind)` to combine them
goal_contribution_df_ALL <- map2(.x = team_links_df$link, 
                             .y = team_links_df$team_name,
                             ~ jleague_stats_info(link = .x) %>% mutate(team = .y))

goal_contribution_df <- goal_contribution_df_ALL %>% 
  reduce(rbind)

# CLEAN data
goal_contribution_clean_df <- goal_contribution_df %>% 
  mutate_at(.vars = c("goals", "assists"), 
            ~str_replace(., "-", "0") %>% as.numeric) %>% 
  mutate(team = team %>% str_replace_all(., "-", " ") %>% str_to_title) %>% 
  group_by(team) %>% 
  mutate(total_goals = sum(goals),
         total_assists = sum(assists),
         goal_contrib = goals/total_goals,
         assist_contrib = assists/total_goals) %>% 
  ungroup()

## save
saveRDS(goal_contribution_clean_df, 
        file = glue("{here::here()}/data/goal_contrib_clean_df.RDS"))
        
goal_contribution_clean_df %>% 
  ggplot(aes(assist_contrib, goal_contrib)) +
  geom_point(data = goal_contribution_clean_df %>%
                    filter(goal_contrib < 0.25 | assist_contrib < 0.15),
             color = "grey20", size = 4, alpha = 0.2) +
  geom_point(data = goal_contribution_clean_df %>%
                    filter(goal_contrib > 0.25 | assist_contrib > 0.15),
             color = "red", size = 4) +
  geom_hline(yintercept = 0.25, color = "grey20", alpha = 0.4) +
  geom_vline(xintercept = 0.15, color = "grey20", alpha = 0.4) +
  geom_text_repel(data = goal_contribution_clean_df %>%
                    filter(goal_contrib > 0.25 | assist_contrib > 0.15),
                  aes(label = name, family = "Roboto Condensed", fontface = "bold"), 
                  seed = 7, size = 5, 
                  min.segment.length = 0, segment.color = "red",
                  point.padding = 0.5) +
  scale_x_continuous(labels = percent_format(accuracy = 1), 
                     breaks = c(0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3),
                     limits = c(0, 0.3)) +
  scale_y_continuous(labels = percent_format(accuracy = 1), 
                     breaks = c(0, 0.1, 0.2, 0.3, 0.4, 0.5),
                     limits = c(0, 0.5)) +
  labs(title = "得点貢献度 (チームのゴール・アシスト割合)",
       subtitle = "J.League 2018 シーズン",
       caption = glue("
                      データ: transfermarkt.com
                      作: @R_by_Ryo"),
       x = "アシスト割合",
       y = tategaki_alt("ゴール割合")) +
  theme_minimal() +
  theme(text = element_text(family = "Roboto Condensed"),
        title = element_text(size = 20),
        plot.subtitle = element_text(size = 18),
        plot.caption = element_text(size = 8),
        axis.title = element_text(size = 15),
        axis.title.y = element_text(angle = 0, vjust= 0.5),
        axis.text = element_text(size = 14),
        panel.grid.minor.x = element_blank()) -> goal_contribution_matrix_jp

ggsave(plot = goal_contribution_matrix_jp, 
       "../J-League 2018/output/goal_contribution_matrix_plot_jp.png",
       height = 8, width = 10)

plot_logo <- add_logo(
  plot_path = "../J-League 2018/output/goal_contribution_matrix_plot_jp.png",
  logo_path = "https://upload.wikimedia.org/wikipedia/en/3/31/J.League_%28local%29.png",
  logo_position = "top right",
  logo_scale = 18)

image_write(image = plot_logo, 
            "../J-League 2018/output/goal_contribution_matrix_plot_jp_logo.png")