Question

与标题中一样，有没有一种方法可以使用purrr和dplyr从列表中提取多个组件？ pluck适用于单个元素，但不适用于少数元素。如下所示：

my_data <- data.frame(group = c(sample(c('A', 'B', 'C'), 20, replace = TRUE)), x = runif(100, 0, 10), y = runif(100, 0, 10))
my_data %>% 
  group_by(group) %>% 
  nest() %>% 
  mutate(km_cluster = map(data, ~kmeans(.x, 3) %>% pluck(c('cluster', 'centers'))))

然后，我想添加有关将观察值分配给data的簇号和簇质心的信息。数据列中单个元素的期望输出如下所示：

structure(list(x = c(7.73117371369153, 0.0510848499834538, 4.55259998561814, 
9.89025634946302, 2.37372878007591, 1.97317335521802), y = 
c(7.59347913088277, 8.7801841692999, 9.11954281385988, 3.90361216617748, 
2.92225106153637, 0.338000932242721), cluster = c(3L, 1L, 1L, 3L, 2L, 2L), 
x_center = c(7.99236144404858, 2.53133282822091, 2.53133282822091, 
7.99236144404858, 3.79731344497379, 3.79731344497379), y_center = 
c(6.60092391962694, 8.42530809265251,8.42530809265251, 6.60092391962694, 
2.02696633155403, 2.02696633155403)), .Names = c("x", "y", "cluster", 
"x_center", "y_center"), row.names = c(NA, 
-6L), class = c("tbl_df", "tbl", "data.frame"))

Answer 1

我们可以在底数R中使用.collapse { flex: 0 0 50%; max-width: 66.6666%; padding: 30px; background-color: red; transition: flex 1000ms ease; } .expand { flex: 0 0 66.66667%; background-color: red; }。

更新

my_data %>% 
  group_by(group) %>% 
  nest() %>% 
  mutate(km_cluster = map(data, ~kmeans(.x, 3) %>% `[`(c("cluster", "centers"))))
# # A tibble: 3 x 3
#   group data              km_cluster
#   <fct> <list>            <list>    
# 1 B     <tibble [25 x 2]> <list [2]>
# 2 C     <tibble [60 x 2]> <list [2]>
# 3 A     <tibble [15 x 2]> <list [2]>

如何从嵌套列中的列表中将多个组件提取到列中

1 个答案: