使用R语言dplyr包的pivot_wider实现多列数据重排

要实现你想要的数据集结构转换，不能直接用pivot_wider，得先把宽格式的物种列转为长格式，再重新调整KUD为列。以下是具体实现步骤：

1. 加载必要的包 #

library(tidyverse)

2. 导入可复现数据集 #

df <- structure(list(Grey.Reef.Shark = c(0.0153693415007032, 0.0743482431216283, 
0.0157723122886768, 0.0718452019326124, 0.0271587991640831, 0.139118848810864
), Silvertip.Shark = c(0.00616969268071902, 0.0677936053733444, 
0.00983240322136223, 0.0926378231217502, 0.0484117524071891, 
0.235938189749556), monthyear = c("2014/01", "2014/01", "2014/02", 
"2014/02", "2014/03", "2014/03"), KUD = structure(c(1L, 2L, 1L, 
2L, 1L, 2L), levels = c("50", "95"), class = "factor")), row.names = c("50", 
"95", "501", "951", "502", "952"), class = "data.frame")

3. 执行数据转换 #

核心是两步：先用pivot_longer把两个鲨鱼物种列合并为species和value列，再用pivot_wider把KUD的不同取值转为列：

result <- df %>%
  # 将物种列转为长格式
  pivot_longer(cols = c(Grey.Reef.Shark, Silvertip.Shark),
               names_to = "species",
               values_to = "value") %>%
  # 将KUD转为宽格式列
  pivot_wider(names_from = KUD,
              values_from = value) %>%
  # 调整列顺序匹配期望格式
  select(`50`, `95`, monthyear, species)

4. 查看转换结果 #

运行上述代码后，输出结果与你期望的格式一致：

print(result)
#> # A tibble: 6 × 4
#>      `50`    `95` monthyear species          
#>     <dbl>   <dbl> <chr>     <chr>            
#> 1 0.0154  0.0743  2014/01   Grey.Reef.Shark  
#> 2 0.00617 0.0678  2014/01   Silvertip.Shark  
#> 3 0.0158  0.0718  2014/02   Grey.Reef.Shark  
#> 4 0.00983 0.0926  2014/02   Silvertip.Shark  
#> 5 0.0272  0.139   2014/03   Grey.Reef.Shark  
#> 6 0.0484  0.236   2014/03   Silvertip.Shark

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