我有一个由两个 Dataframe 组成的列表。在此基础上，我创建了一个带有数值变量的矩阵。在下一步中，我试图根据原始列表的列将行名称设置为矩阵。然而，这不起作用。将行名称设置为原始列表确实有效。有人知道问题在哪里吗？

install.packages("purrr")
library(purrr)

# Data
data1 <- data.frame(new_id = c("y", "z"), met1 = c(20, 25),  met2 = c(20, 25))
data2 <- data.frame(new_id = c("b", "c"), met1 = c(5, 15), met2 =c(22, 24))

my_list <- list(data1, data2) # List of two dataframes

my_list
#> [[1]]
#>   new_id met1 met2
#> 1      y   20   20
#> 2      z   25   25
#> 
#> [[2]]
#>   new_id met1 met2
#> 1      b    5   22
#> 2      c   15   24

# Set row names: new_id
my_list1 <- my_list %>% 
    purrr::map(~data.frame(.x, row.names = .x$new_id)) # Works

my_list1
#> [[1]]
#>   new_id met1 met2
#> y      y   20   20
#> z      z   25   25
#> 
#> [[2]]
#>   new_id met1 met2
#> b      b    5   22
#> c      c   15   24

# Convert "my_list" into matrix and select numeric vars met1 and met2
matrix <- my_list %>% 
   purrr::map(~dplyr::select(.x, met1, met2)) %>% 
   purrr::map(as.matrix)
 
# Convert "num_slct" to matrix and set row.names
  matrix %>% 
  purrr::map(~.x, row.names = my_list$new_id) # set row.names does not work
#> [[1]]
#>      met1 met2
#> [1,]   20   20
#> [2,]   25   25
#> 
#> [[2]]
#>      met1 met2
#> [1,]    5   22
#> [2,]   15   24

创建于2020-04-14由reprex package（v0.3.0）