R pivot_longer 结合了几列

Question

我有一个数据框，其中几列具有相似的信息，我想将它们折叠成更少的列。这似乎与 pivot_long 或 collect 的正常使用有点不同，我被卡住了。我的第一个想法是制作 3 个单独的集合和行绑定.. 但我认为这里有人会有更优雅的解决方案！

df<-data.frame("PicID"=letters[1:8],
"Near_Species1" = c("bird","bird", "bird", "dog", "dog", "human", "none", "human"),
"Count1" = c(1,1,1,1,2,1,0,1),
"Near_Species2" = c(NA,"human", NA, NA, "human", NA, NA, NA), 
"Count2" = c(NA,1, NA, NA, 1, NA, NA, NA),
"Far_Species"=c(NA, NA, NA,NA, NA, NA, NA, "bird"))

我想用

的基本结构来延长这个时间

PicID   NearorFar   Species   Count

我希望基于 Near_Species1 每张图片至少有 1 行，无论那里有什么（无、NA 等）。

如果在 Near_Species2、Count2 或 Far_Species 中有“无”以外的任何物种，我想要另一行。本质上，物种的“无”是 NA。但我希望至少有 1 行来跟踪该 ID。

输出看起来像这样，但删除了 species 为 NA 的行。

df_out <- data.frame(
  "PicID" = c("a", "b", "c", "d", "e", "f", "g", "h", 
          "a", "b", "c", "d", "e", "f", "g", "h", 
          "a", "b", "c", "d", "e", "f", "g", "h"),
"NearorFar"=rep(c("Near", "Far"),times=c(16, 8)),
"Species"= paste(c("bird","bird", "bird", "dog", "dog", "human", "none", "human", 
                NA,"human", NA, NA, "human", NA, NA, NA, 
                NA, NA, NA,NA, NA, NA, NA, "bird")),
"Count"= c(1,1,1,1,2,1,0,1,
          NA,1, NA, NA, 1, NA, NA, NA, 
          rep(NA, 8))
)

Answer 1

我们可以使用pivot_longer

library(dplyr)
library(tidyr)
library(stringr)
df %>% 
  pivot_longer(cols = matches('Species'), names_to = 'NearorFar', 
         values_to = 'Species') %>% 
  mutate(NearorFar = str_remove(NearorFar, "_.*")) %>% 
  pivot_longer(cols = starts_with('Count'), names_to = NULL, 
          values_to = 'Count', values_drop_na = TRUE) %>% 
  distinct