使用 igraph 对象递归循环邻居

Question

感谢任何指向以下所需输出的指针。我知道我需要进行某种形式的递归，但确定如何准确地做到这一点。

我有以下代码

>> start of code
# BOM data
library("dplyr")
library(igraph)

text1 <- ("
          matnr,comp
          FG1,SA1
          FG1,SA2
          SA1,SA3
          SA1,SA4
          SA1,SA5
          SA5,SA6
          FG2,SA1
          FG2,SA8
          SA8,SA9
          SA9,SA10
          SA9,SA11")

df1 <- read.table(textConnection(text1),  header = TRUE, stringsAsFactors=FALSE, strip.white = TRUE, sep=",")
head(df1)
net <- graph_from_data_frame(df1)
net
neighbors_FG1 <- neighbors(net, v=c("FG1"), mode=c("out"))
neighbors_FG1

neighbors_FG2 <- neighbors(net, v=c("FG2"), mode=c("out"))
neighbors_FG2            

neighbors_SA1 <- neighbors(net, v=c("SA1"), mode=c("out"))
neighbors_SA1

>> end of code

我希望能够生成如下所示的数据框。我认为这需要某种递归，我想获得这方面的帮助。如果您甚至可以帮助我获得下面的输出，那就太好了。

FG,level,material,Comp  
FG1,1,FG1,SA1  
FG1,1,FG1,SA2  
FG1,2,SA1,SA3  
FG1,2,SA1,SA4  
FG1,2,SA1,SA5  
FG1,3,SA5,SA6  
FG2,1,FG2,SA1  
FG2,1,FG2,SA8  
FG2,2,SA8,SA9  

Answer 1

这是一个igraph选项

lst <- lapply(
  names(V(net))[degree(net, mode = "in") == 0],
  function(x) {
    d <- Filter(
      is.finite,
      setNames(
        c(distances(net, x, mode = "out") + 1),
        names(V(net))
      )
    )
    cbind(
      FG = x,
      merge(
        setNames(get.data.frame(
          induced_subgraph(
            net,
            names(d)
          )
        ), c("matnr", "comp")),
        setNames(
          rev(stack(d)),
          c("matnr", "lvl")
        )
      )
    )
  }
)

res <- `row.names<-`(
  subset(
    do.call(rbind, lst),
    ave(seq_along(matnr), matnr, comp, lvl, FUN = seq_along) == 1
  ), NULL
)

这给出了

> res
    FG matnr comp lvl
1  FG1   FG1  SA1   1
2  FG1   FG1  SA2   1
3  FG1   SA1  SA3   2
4  FG1   SA1  SA4   2
5  FG1   SA1  SA5   2
6  FG1   SA5  SA6   3
7  FG2   FG2  SA1   1
8  FG2   FG2  SA8   1
9  FG2   SA8  SA9   2
10 FG2   SA9 SA10   3
11 FG2   SA9 SA11   3