是否有一种“tidyverse”方式来加入 data.frames 列表(a la full_join()
,但对于 >2 个 data.frames)?由于调用 map()
,我有一个 data.frames 列表。 .我用过 Reduce()
之前做这样的事情,但想将它们合并为管道的一部分 - 只是还没有找到一种优雅的方法来做到这一点。玩具示例:
library(tidyverse)
## Function to make a data.frame with an ID column and a random variable column with mean = df_mean
make.df <- function(df_mean){
data.frame(id = 1:50,
x = rnorm(n = 50, mean = df_mean))
}
## What I'd love:
my.dfs <- map(c(5, 10, 15), make.df) #%>%
# <<some magical function that will full_join() on a list of data frames?>>
## Gives me the result I want, but inelegant
my.dfs.joined <- full_join(my.dfs[[1]], my.dfs[[2]], by = 'id') %>%
full_join(my.dfs[[3]], by = 'id')
## Kind of what I want, but I want to merge, not bind
my.dfs.bound <- map(c(5, 10, 15), make.df) %>%
bind_cols()
最佳答案
我们可以使用 Reduce
set.seed(1453)
r1 <- map(c(5, 10, 15), make.df) %>%
Reduce(function(...) full_join(..., by = "id"), .)
或者这可以通过
reduce
来完成library(purrr)
set.seed(1453)
r2 <- map(c(5, 10, 15), make.df) %>%
reduce(full_join, by = "id")
identical(r1, r2)
#[1] TRUE
关于r - 从 map() 调用加入 data.frames 列表,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/41147372/