r - full_join 通过变量作为列名

Question

我正在尝试使用 dplyr 的 full_join组合两个data.frames，例如:

col1 = 'b'
col2 = 'd'

df1 = data.frame(a = 1:3, b = 1:3)
df2 = data.frame(a = 1:3, d = 1:3)


full_join(df1, df2, c('a' = 'a', col1 = col2))

但它返回

Error: by can't contain join column col1 which is missing from LHS

我正在寻找类似于的输出

merge(df1, df2, by.x = c('a', col1), by.y = c('a', col2))
  a b
1 1 1
2 2 2
3 3 3

Answer 1

您可以使用 rename_ ， IE。，

library(dplyr)

full_join(df1, rename_(df2, .dots = setNames(col2, col1)))

这使，

#Joining, by = c("a", "b")
  a b
1 1 1
2 2 2
3 3 3

根据@akrun 和@mt1022 评论发布替代方案，

#akrun
full_join(df1, rename_at(df2, .vars = col2, funs(paste0(col1))))
full_join(df1, rename(df2, !!(col1) := !!rlang::sym(col2)))

#mt1022
full_join(df1, rename_at(df2, col2, ~col1))