根据 R 中的逻辑向量过滤嵌套的数据帧列表答案

【问题标题】：Filter a nested list of dataframes based on logical vector in R根据 R 中的逻辑向量过滤嵌套的数据帧列表
【发布时间】：2021-01-14 20:01:08
【问题描述】：

我有一个嵌套的坐标列表：

coords <- list(`41` = structure(list(lon = c(11.9170235974052, 11.9890348226944,11.9266305690725), 
                                     lat = c(48.0539406017157, 48.0618200883643,48.0734094557987)), 
                                class = "data.frame", row.names = c(NA, -3L )),
               `51` = structure(list(lon = c(11.9700157009047, 11.9661664366154,11.9111812165745), 
                                     lat = c(48.0524843177559, 48.0645786453912, 48.0623193233537)), 
                                class = "data.frame", row.names = c(NA, -3L)), 
               `61` = structure(list(lon = c(11.9464237941416, 11.9536554768081,11.9112311461624), 
                                     lat = c(48.040970408282, 48.0408864989903, 48.0284615642167)), 
                                class = "data.frame", row.names = c(NA, -3L )), 
               `71` = structure(list(lon = c(11.9274864543974, 11.8733675039864,11.933264512569), 
                                     lat = c(48.0135478382282, 48.0216452485664, 48.0289752363299)), 
                                class = "data.frame", row.names = c(NA, -3L)), 
               `81` = structure(list(lon = c(11.8837173493491, 11.9072450330566,11.8943898749275), 
                                     lat = c(48.0266639859759, 48.0132853717376, 48.0327326995006)), 
                                class = "data.frame", row.names = c(NA, -3L )), 
               `91` = structure(list(lon = c(11.882538477087, 11.8377742591454,11.8817027393128), 
                                     lat = c(48.0284081468982, 48.022864811514, 48.0229810559649)), 
                                class = "data.frame", row.names = c(NA, -3L )))

我想根据嵌套的逻辑值列表过滤此列表。

 index <- list(`41` = c(TRUE, TRUE, FALSE), `51` = c(FALSE, FALSE, TRUE
), `61` = c(FALSE, FALSE, FALSE), `71` = c(FALSE, FALSE, FALSE
), `81` = c(FALSE, FALSE, FALSE), `91` = c(FALSE, FALSE, FALSE))

这样做的最佳方法是什么？我试图取消列出嵌套列表或创建一个 data.frame 但没有成功。谢谢！

【问题讨论】：

标签： r data.table tidyr

【解决方案1】：

你可以像这样使用Map：

Map(function(x, y) x[y, ], coords, index)

#$`41`
#       lon      lat
#1 11.91702 48.05394
#2 11.98903 48.06182

#$`51`
#       lon      lat
#3 11.91118 48.06232

#$`61`
#[1] lon lat
#<0 rows> (or 0-length row.names)
#...
#...

在tidyverse：

library(purrr)
library(dplyr)

map2(coords, index, ~.x %>% filter(.y))

【讨论】：

【解决方案2】：

This answer 可以很好地将列表转换为数据框。如果顺序一致，那么我认为这就是您所需要的

library(purrr)
# use solution to convert lists to dataframes, storing the names in id column
coords_df <- map_df(coords, ~as.data.frame(.x), .id="id")
index_df <- map_df(index, ~as.data.frame(.x), .id="id")
# filter coordinates on the values in index
coords_df[index_df$.x,]

【讨论】：