如何在R中重新分组列

library(dplyr)

df <- df %>% 
  group_by(column_name)

df <- df %>% 
  summarize(mean_value = mean(column_name))

library(dplyr)

# 创建示例数据框
df <- data.frame(
  group_column = c("A", "A", "B", "B", "C"),
  value_column = c(1, 2, 3, 4, 5)
)

# 按照group_column列进行分组，并计算每个分组的平均值
df <- df %>% 
  group_by(group_column) %>% 
  summarize(mean_value = mean(value_column))

# 输出结果
print(df)