r - R中跨列的条件变异

Question

假设你有一个 tibble像这样:

library(tidyverse)

df<-tibble(person = c("Alice", "Bob", "Mary"),
          likes_cheese = c("yes", "yes", NA),
          likes_ham = c("no", "yes", "yes"))

# A tibble: 3 x 3
  person likes_cheese likes_ham
  <chr>  <chr>        <chr>    
1 Alice  yes          no       
2 Bob    yes          yes      
3 Mary   NA           yes     

如何有条件地改变连接字符串的新列？我需要一个可以忽略 NA 的解决方案。

预期结果:

tibble(person = c("Alice", "Bob", "Mary"),
       favourite_food = c("cheese", "cheese, ham", "ham"))

# A tibble: 3 x 2
  person favourite_food
  <chr>  <chr>         
1 Alice  cheese        
2 Bob    cheese, ham   
3 Mary   ham   

Answer 1

 df %>%
  mutate(
    favorite_food = paste0(
      if_else(likes_cheese == "yes" & !is.na(likes_cheese), "cheese,", ""),
      if_else(likes_ham == "yes" & !is.na(likes_ham), "ham", "")
    )
  ) %>% 
  select(-starts_with("likes"))

# A tibble: 3 x 2
  person favorite_food
  <chr>  <chr>        
1 Alice  cheese,      
2 Bob    cheese,ham   
3 Mary   ham