Question

我有一个图表对象g_sub，并希望在v_matches中创建一组顶点g附近的子图order，{{1} } 1.5。

换句话说，我想找到哪些顶点连接到v_matches（顺序1），哪些顶点连接到顺序== 1顶点当且仅当这些顶点是也连接到v_matches顶点。

在非技术术语中，我想找到朋友的朋友（订单2），前提是这些朋友也是我的朋友（订单1.5）＆＃39;。我找不到在igraph中轻松完成此操作的方法。

我编写的代码计算v_matches的第2阶邻域，但我希望它计算1.5阶。非常感谢任何帮助。

v_matches <- which(V(g)$SomeVertexAttribute==SomeValue)

g_sub <- induced.subgraph(graph=g,vids=unlist(neighborhood(g,order=2,nodes=v_matches)))

更新：这是一个函数和我编写的一些代码，用于将order=2子图转换为order 1.5。但是，我不相信它运作正常。

Order2ToOrder1.5 <- function(g_sub,categoryValue) {
  # get the new indexes of the 'ego' sites for the subgraph
  matches_subgraph_gsub <- which(V(g_sub)$`Categorical 1`==categoryValue)
  # get the edge list of the subgraph
  edgelistTemp <- get.edgelist(g_sub)
  # get unique "from" values
  uniqueFrom <- unique(edgelistTemp[,1])

  badVerts <- c() # yes, I know it is bad form to append to a vector using a for loop...
  for (i in 1:length(uniqueFrom)){
    # we find the immediate neighbours of each vertice
    tempGraph <- as.vector(neighborhood(graph=g_sub,order=1,nodes=uniqueFrom[i])[[1]])
    # if the neighbourhood does not contain one of the 'ego' sites (i.e. in matches_subgraph_gsub), then we flag this vertex for deletion
    matchTemp <- match(tempGraph,matches_subgraph_gsub)
    if (length(which(is.na(matchTemp)))==length(matchTemp)) {badVerts <- append(badVerts,uniqueFrom[i])}
  }

  # now we can delete these from the subgraph:
  g_return <- delete.vertices(g_sub,badVerts)
}

categoryValue <- 21
matches <- which(V(g)$`Categorical 1`==categoryValue)
g_sub <- induced.subgraph(graph=g,vids=unlist(neighborhood(graph=g,order=2,nodes=matches)))

# We can use the new function to convert from order2 to order1.5:
g_sub_1.5 <- Order2ToOrder1.5(g_sub,categoryValue)

如何计算1.5阶图的邻域？

0 个答案: