如何格式化组合柱状图与折线图（含代码调整需求）

# 输入数据
year <- c("2001", "2002", "2003", "2004", "2005", "2006", "2007", "2008", "2009",
          "2010", "2011", "2012", "2013", "2014", "2015", "2016", "2017", "2018", 
          "2019", "2020", "2021", "2022", "2023")

failures <- c(4, 11, 3, 4,  0,  0,  3,  25, 140, 157, 92, 51, 24, 18, 8,
              5, 8, 0, 4, 4, 0, 0, 3)

assets <- c(2358.6, 2705.4, 1045.2, 163.1,  0,  0,  2602.5, 373588.8,   
            170909.4, 96514, 36012.2, 12055.8, 6101.7, 3088.4, 
            6727.5, 278.8, 6530.7, 0, 214.1, 458, 0, 0, 548500)

# 合并为数据框（原代码缺失此步骤）
banks <- data.frame(year, failures, assets)

# 加载所需包
library(ggplot2)
library(scales)

# 绘制组合图
ggplot(banks, aes(x = year)) +  
  geom_col(aes(y = failures), size = 1, color = "dodgerblue4", fill = "white") +
  geom_line(aes(y = failures * (max(assets)/max(failures))), size = 1.5, color = "darkorange2", group = 1) +
  scale_y_continuous(
    name = "Number of Bank Failures",  # 修改主Y轴标题
    limits = c(0, max(failures) * 1.05),  # 调整主Y轴缩放，确保柱状图清晰
    sec.axis = sec_axis(
      ~ . / (max(assets)/max(failures)),  # 匹配主副轴比例，优化可视化
      name = "Total Assets ($M)",
      labels = dollar_format(prefix = "$", big.mark = ",")  # 设置次Y轴数值格式为$100,000样式
    )
  ) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1))  # 可选：旋转X轴标签避免重叠

关键修改说明 #

• 补全数据框定义：原代码直接使用banks但未创建，新增banks <- data.frame(year, failures, assets)
• 主Y轴标题设置：通过scale_y_continuous的name参数指定为要求的标题
• 次Y轴格式优化：借助scales包的dollar_format()实现带美元符号和千分位的数值显示
• Y轴缩放调整：
  • 主Y轴设置上下限为0到最大倒闭数的1.05倍，保证柱状图完整展示
  • 用max(assets)/max(failures)计算主副轴比例，让折线图与柱状图的缩放匹配，避免一方被压缩

内容的提问来源于stack exchange，提问作者Data and AI Nerd