R语言UsingR包npdb数据集金额统计与图表实现问题咨询

先加载所需依赖和数据集，所有后续代码均基于此环境运行：

# 加载数据集包
library(UsingR)
data(npdb)
# 如使用tidyverse语法/ggplot2可视化，需提前加载对应包
library(dplyr)
library(ggplot2)

1. 计算每个ear对应总金额并生成饼图 #

先按ear分组求和得到总金额，再传入绘图函数即可：

# 按ear分组计算总金额
ear_amount_sum <- aggregate(amount ~ ear, npdb, sum)

# 基础R绘图版饼图
pie(ear_amount_sum$amount, labels = ear_amount_sum$ear, main = "各ear总金额占比")

# ggplot2美化版饼图
ggplot(ear_amount_sum, aes(x = "", y = amount, fill = as.factor(ear))) +
  geom_col(color = "white") +
  coord_polar(theta = "y") +
  labs(title = "各ear总金额占比", fill = "ear") +
  theme_void()

2. 提取每个州最高金额对应的记录及ID #

按州分组后取金额最高的行即可，可自行调整参数控制是否保留并列最高的记录：

state_top_records <- npdb %>%
  group_by(state) %>%
  # with_ties设为TRUE可保留同一州多个相同最高金额的记录，设为FALSE仅取第一条
  slice_max(amount, n = 1, with_ties = FALSE) %>%
  select(state, ID, amount)

# 输出所有州的结果
print(state_top_records, n = Inf)

3. 绘制金额数据的直方图 #

直接传入金额列绘图即可，由于金额数据普遍右偏，可选择对数转换后绘制以获得更清晰的分布特征：

# 基础R绘图版原始金额直方图
hist(npdb$amount, breaks = 30, col = "lightblue", main = "金额分布直方图", xlab = "金额")
# 基础R绘图版对数转换后金额直方图
hist(log(npdb$amount), breaks = 30, col = "lightgreen", main = "对数转换后金额分布直方图", xlab = "log(金额)")

# ggplot2版原始金额直方图
ggplot(npdb, aes(x = amount)) +
  geom_histogram(bins = 30, fill = "lightblue", color = "black") +
  labs(title = "金额分布直方图", x = "金额", y = "频数") +
  theme_minimal()

# ggplot2版对数转换后金额直方图
ggplot(npdb, aes(x = log(amount))) +
  geom_histogram(bins = 30, fill = "lightgreen", color = "black") +
  labs(title = "对数转换后金额分布直方图", x = "log(金额)", y = "频数") +
  theme_minimal()

内容的提问来源于stack exchange，提问作者MiRAY