返回嵌套級別和值的嵌套列表

Question

我想使用networkD3可視化一些深度嵌套的數據。在發送到radialNetwork之前，我無法弄清楚如何將數據轉換爲正確的格式。

下面是一些示例數據：

level <- c(1, 2, 3, 4, 4, 3, 4, 4, 1, 2, 3) 
value <- letters[1:11] 

其中level表示巢的水平，並且value是節點的名稱。通過使用這兩個向量，我需要將數據放到以下格式：

my_list <- list(
    name = "root", 
    children = list(
    list(
     name = value[1], ## a 
     children = list(list(
     name = value[2], ## b 
     children = list(list(
      name = value[3], ## c 
      children = list(
      list(name = value[4]), ## d 
      list(name = value[5]) ## e 
     ) 
     ), 
     list(
      name = value[6], ## f 
      children = list(
      list(name = value[7]), ## g 
      list(name = value[8]) ## h 
     ) 
     )) 
    )) 
    ), 
    list(
     name = value[9], ## i 
     children = list(list(
     name = value[10], ## j 
     children = list(list(
      name = value[11] ## k 
     )) 
    )) 
    ) 
) 
) 

這裏是deparsed對象：

> dput(my_list) 
# structure(list(name = "root", 
#    children = list(
#     structure(list(
#     name = "a", 
#     children = list(structure(
#      list(name = "b", 
#       children = list(
#        structure(list(
#        name = "c", children = list(
#         structure(list(name = "d"), .Names = "name"), 
#         structure(list(name = "e"), .Names = "name") 
#        ) 
#       ), .Names = c("name", 
#           "children")), structure(list(
#            name = "f", children = list(
#            structure(list(name = "g"), .Names = "name"), 
#            structure(list(name = "h"), .Names = "name") 
#           ) 
#           ), .Names = c("name", 
#               "children")) 
#       )), .Names = c("name", "children") 
#     )) 
#     ), .Names = c("name", 
#        "children")), structure(list(
#         name = "i", children = list(structure(
#         list(name = "j", children = list(structure(
#          list(name = "k"), .Names = "name" 
#         ))), .Names = c("name", 
#             "children") 
#         )) 
#        ), .Names = c("name", "children")) 
#    )), 
#   .Names = c("name", 
#      "children")) 

然後我就可以把它傳遞給最終的繪圖功能：

library(networkD3) 
radialNetwork(List = my_list) 

輸出將類似於此：

---

問題：如何創建嵌套列表？

注意：正如@ zx8754所指出的那樣，這個SO post已經有一個解決方案，但這需要data.frame作爲輸入。由於我的level不一致，我沒有看到簡單的方法將其轉換爲data.frame。

Answer 1

使用data.table式的合併：

library(data.table) 
dt = data.table(idx=1:length(value), level, parent=value) 

dt = dt[dt[, .(i=idx, level=level-1, child=parent)], on=.(level, idx < i), mult='last'] 

dt[is.na(parent), parent:= 'root'][, c('idx','level'):= NULL] 

> dt 
#  parent child 
# 1: root  a 
# 2:  a  b 
# 3:  b  c 
# 4:  c  d 
# 5:  c  e 
# 6:  b  f 
# 7:  f  g 
# 8:  f  h 
# 9: root  i 
# 10:  i  j 
# 11:  j  k 

現在我們可以使用來自其他post解決方案：

x = maketreelist(as.data.frame(dt)) 

> identical(x, my_list) 
# [1] TRUE 

Answer 2

作爲序言，你的數據是很難，因爲關鍵信息工作按照level中的值的順序進行編碼。我不知道你是如何按照這個順序得到這些值的，但考慮到可能有更好的方法來構建這些信息，這將使下一個任務更容易。

這裏的轉換數據到數據幀2列，parent和child，然後傳遞到這一點data.tree功能，可以很容易地轉換到你需要的JSON格式的base -y方式......然後把它傳遞到radialNetwork ...

level <- c(1, 2, 3, 4, 4, 3, 4, 4, 1, 2, 3) 
value <- letters[1:11] 

library(data.tree) 
library(networkD3) 

parent_idx <- sapply(1:length(level), function(n) rev(which(level[1:n] < level[n]))[1]) 
df <- data.frame(parent = value[parent_idx], child = value, stringsAsFactors = F) 
df$parent[is.na(df$parent)] <- "" 

list <- ToListExplicit(FromDataFrameNetwork(df), unname = T) 
radialNetwork(list) 

這裏是達到相同的tidyverse方式...

level <- c(1, 2, 3, 4, 4, 3, 4, 4, 1, 2, 3) 
value <- letters[1:11] 

library(tidyverse) 
library(data.tree) 
library(networkD3) 

data.frame(level, value, stringsAsFactors = F) %>% 
    mutate(row = row_number()) %>% 
    mutate(level2 = level, value2 = value) %>% 
    spread(level2, value2) %>% 
    mutate(`0` = "") %>% 
    arrange(row) %>% 
    fill(-level, -value, -row) %>% 
    gather(parent_level, parent, -level, -value, -row) %>% 
    filter(parent_level == level - 1) %>% 
    arrange(row) %>% 
    select(parent, child = value) %>% 
    data.tree::FromDataFrameNetwork() %>% 
    data.tree::ToListExplicit(unname = TRUE) %>% 
    radialNetwork() 

和獎金，012目前的開發版本（v0.4.9000）有一個新的treeNetwork函數，它需要一個包含nodeId和parentId列/變量的數據幀，這消除了將data.tree函數轉換爲JSON的需要，所以類似這樣的工作...

level <- c(1, 2, 3, 4, 4, 3, 4, 4, 1, 2, 3) 
value <- letters[1:11] 

library(tidyverse) 
library(networkD3) 

data.frame(level, value, stringsAsFactors = F) %>% 
    mutate(row = row_number()) %>% 
    mutate(level2 = level, value2 = value) %>% 
    spread(level2, value2) %>% 
    mutate(`0` = "root") %>% 
    arrange(row) %>% 
    fill(-level, -value, -row) %>% 
    gather(parent_level, parent, -level, -value, -row) %>% 
    filter(parent_level == level - 1) %>% 
    arrange(row) %>% 
    select(nodeId = value, parentId = parent) %>% 
    rbind(data.frame(nodeId = "root", parentId = NA)) %>% 
    mutate(name = nodeId) %>% 
    treeNetwork(direction = "radial")