R 如何仅查找某些顶点的邻域？

问题开始了

---

我有一个带有

n的无向图
g
，函数是正确的，但第二个参数不是关于感兴趣的顶点，它是第三个：

neighborhood
# function (graph, order = 1, nodes = V(graph), mode = c("all", 
#     "out", "in"), mindist = 0) 
# {
# ...

因此,

他做这项工作

idv <- V(g)[strength(g)==2]; idv # 1 2 3 5 6 7 9

neigh<-neighborhood(g, idv); neigh

neigh[[4]]; neigh[[8]];   
#[1] 4 3 5 9
#[1] 8 1 7 9

neighborhood
# function (graph, order = 1, nodes = V(graph), mode = c("all", 
#     "out", "in"), mindist = 0) 
# {
# ...

length(neighborhood(g, nodes = idv))
# [1] 7