R DataFrame列转行操作：列名转为Type列值，对应值存入Count列

方法1：使用tidyverse套件（推荐） #

library(tidyverse)

# 转换宽表为长表，同时修正原列名拼写错误
Unp_long <- Unp %>%
  pivot_longer(
    cols = -Week, # 排除Week列，其余列都做转换
    names_to = "Type", # 原列名存储到Type列
    values_to = "Count" # 原数值存储到Count列
  ) %>%
  # 修正原累计目标列的拼写错误（Cumilative→Cumulative）
  mutate(Type = recode(Type, "Cumilative target" = "Cumulative target"))

转换后前6行输出示例：

# A tibble: 40 × 3
   Week       Type              Count
   <date>     <chr>             <dbl>
 1 2019-01-07 Target                5
 2 2019-01-07 Cumulative target     5
 3 2019-01-14 Target                8
 4 2019-01-14 Cumulative target    13
 5 2019-01-21 Target               15
 6 2019-01-21 Cumulative target    28

方法2：基础R实现（无需额外安装包） #

Unp_long <- reshape(
  Unp,
  idvar = "Week", # 主键列
  varying = list(c("Target", "Cumilative target")), # 需要转换的列
  v.names = "Count", # 数值列名
  timevar = "Type", # 类型列名
  times = c("Target", "Cumulative target"), # Type列的取值
  direction = "long" # 转换方向为长表
)
rownames(Unp_long) <- NULL # 重置行号

内容的提问来源于stack exchange，提问作者firmo23