用 Ruby 进行数据可视化与桌面报告生成
1. 使用 Gruff 创建柱状图
在数据可视化中，柱状图是一种常用的展示方式。以下代码展示了如何使用 Gruff 库为数据库中的每个玩家创建柱状图报告：
Player.find(:all).each do |player| bar_chart = Gruff::Bar.new(1024) bar_chart.legend_font_size = 12 total_games = Play.count(:conditions=>['game_id = ? ' << 'AND player_id = ?', game_id_to_analyze, player.id]).to_f total_wins = Play.count(:conditions=>['game_id = ? ' << 'AND player_id = ? ' << 'AND won=1', game_id_to_analyze, player.id]).to_f win_ratio = (total_wins / total_games * 100).to_i unless total_games == 0 win_ratio ||= 0 bar_chart.title = "#{player.name} " << "(#{win_ratio}% won)" bar_chart.minimum_value = 0 bar_chart.maximum_value = 110 sql
