如何根據值列表擴展小標題中的行

Question

我有這一行

  first coor  second
  <chr> <chr> <chr> 
1 first ALL   second

我想將此行擴展為多行並根據以下值替換 coor 列

coor = c("ESP", "FRA", "GER")

所以我最終得到了這個

  first coor  second
  <chr> <chr> <chr> 
1 first ESP   second
2 first FRA   second
3 first GER   second

有任何想法嗎？

Answer 1

另一種選擇是：

1. 重命名向量
2. 使用slice將 dataframe 擴展為向量的長度
3. 用向量填充coor

library(dplyr)

vec_coor <- coor

dat %>% 
  slice(rep(1:n(), each = length(vec_coor))) %>% 
  mutate(coor = vec_coor)

 first coor  second
  <chr> <chr> <chr> 
1 first ESP   second
2 first FRA   second
3 first GER   second

Answer 2

我們可以創建一個list列並將其unnest

library(dplyr)
library(tidyr)
dat %>%
    mutate(coor = list(.env$coor)) %>% 
    unnest(coor)

-輸出

# A tibble: 3 × 3
  first coor  second
  <chr> <chr> <chr> 
1 first ESP   second
2 first FRA   second
3 first GER   second

---

或者另一種選擇是使用“coor”向量crossing數據子集

crossing(dat %>%
           select(-coor), coor)
# A tibble: 3 × 3
  first second coor 
  <chr> <chr>  <chr>
1 first second ESP  
2 first second FRA  
3 first second GER  

數據

dat <- tibble(first = "first", coor = "ALL", second = "second")
coor <- c("ESP", "FRA", "GER")

Answer 3

另一個解決方案：

library(tidyverse)

df <- data.frame(
  stringsAsFactors = FALSE,
             first = c("first"),
              coor = c("ALL"),
            second = c("second")
      )

df %>% 
  complete(first, coor=c("ESP", "FRA", "GER"), second) %>% filter(!coor == "ALL")

#> # A tibble: 3 × 3
#>   first coor  second
#>   <chr> <chr> <chr> 
#> 1 first ESP   second
#> 2 first FRA   second
#> 3 first GER   second

Answer 4

這是另一種選擇。 我們可以創建一個查找表並應用full_join 。 dat和coor來自 akrun 的回答。

library(tidyverse)

lookup <- data.table(
  coor = rep("ALL", length(coor)),
  coor_new = coor
)

dat2 <- dat %>%
  full_join(lookup, by = "coor") %>%
  select(first, coor = coor_new, second)

dat2
# # A tibble: 3 x 3
#   first coor  second
#   <chr> <chr> <chr> 
# 1 first ESP   second
# 2 first FRA   second
# 3 first GER   second