R语言宽格式数据转长格式避免时间变量前出现X的方法咨询

问题背景 #

当前持有的宽格式数据集示例如下：

需要转换为如下长格式，且时间变量名前不自动添加X前缀：

最简实现方案 #

用tidyverse生态的pivot_longer函数即可直接实现，操作步骤如下：

1. 依赖包加载 #

library(tidyverse)

2. 示例数据构造 #

df <- structure(list(X1 = c("01/12/2019", "02/12/2019"), `00:30` = c(41.95, 39.689), `01:00` = c(44.96, 40.47), `01:30` = c(42.939, 38.95), `02:00` = c(43.221, 40.46), `02:30` = c(44.439, 41.97)), class = "data.frame", row.names = c(NA, -2L), spec = structure(list(cols = list(X1 = structure(list(), class = c("collector_character", "collector")), `00:30` = structure(list(), class = c("collector_double", "collector")), `01:00` = structure(list(), class = c("collector_double", "collector")), `01:30` = structure(list(), class = c("collector_double", "collector")), `02:00` = structure(list(), class = c("collector_double", "collector")), `02:30` = structure(list(), class = c("collector_double", "collector"))), default = structure(list(), class = c("collector_guess", "collector")), skip = 1L), class = "col_spec"))

3. 宽转长核心代码 #

df_long <- df %>%
  pivot_longer(
    cols = -X1,
    names_to = "时间",
    values_to = "数值"
  )

避免X前缀的注意事项 #

• 从数据源导入时直接加check.names=FALSE参数，可从根源避免R自动给非标准列名加X前缀：

  # 以csv导入为例
  df <- read.csv("你的数据文件路径.csv", check.names = FALSE)
  

• 如果已经导入的数据列名已带X前缀，可在转换后加一步去前缀操作：

  df_long <- df %>%
    pivot_longer(cols = -X1, names_to = "时间", values_to = "数值") %>%
    mutate(时间 = str_remove(时间, "^X"))
  

内容的提问来源于stack exchange，提问作者Rstudent