如何使用dplyr计算R语言数据集各因子分组内的数值占比

解决代码 #

首先确认你要的占比是按国家（country）分组，计算当前行value占所属国家所有value总和的比例，实现代码如下：

# 加载dplyr包
library(dplyr)

# 构造示例数据集
data <- data.frame(
  team = c("a", "a", "a", "b", "b", "b", "c", "c", "c"),
  country = c("usa","uk",
              "spain","usa","uk","spain","usa","uk","spain"),
  value = c(40, 20, 10, 50, 30, 35, 50, 60, 25)
)

# 计算得到目标结果
desired_result <- data %>%
  group_by(country) %>%
  mutate(prop = value / sum(value)) %>%
  ungroup()

逻辑验证 #

你给出的desired数据集的prop列数值和按上述逻辑计算的结果完全匹配：

• usa分组总value = 40 + 50 + 50 = 140，对应a队usa占比40/140≈0.2857，与预期一致
• uk分组总value = 20 + 30 + 60 = 110，对应a队uk占比20/110≈0.1818，与预期一致
• spain分组总value = 10 +35 +25 =70，对应a队spain占比10/70≈0.1429，与预期一致

内容的提问来源于stack exchange，提问作者michael_2021