如何从给定的图创建两个子图

How to create two subgraphs from a given graph

假设给定的有向图 G 具有 N 个顶点和 M 个边。
如何从图 G 的现有 M 连接创建两个子图 S_1S_2。这些各自的子图各有一半的现有边。此外,它是由随机性决定的,一条边是属于 S_1 还是 S_2.

示例:

G <- erdos.renyi.game(5,p=0.5,directed = TRUE)
E(G)
> + 12/12 edges:
> [1] 1->5 2->1 4->1 5->1 1->2 3->2 5->2 1->3 3->5 5->3 2->4 3->4

应在 12 个现有边中随机选择 M/2=6 个边,它们代表 S_1 中的边。其余 6 条边提供的边是 S_2.

可能我误会你了:

library(igraph)
set.seed(1)     # for reproducible example
G <- erdos.renyi.game(5,p=0.5,directed = TRUE) 
E(G) 
# Edge sequence:
#           
# [1] 1 -> 5
# [2] 3 -> 1
# [3] 3 -> 2
# [4] 4 -> 2
# [5] 1 -> 3
# [6] 2 -> 3
# [7] 3 -> 5
# [8] 2 -> 4
# [9] 5 -> 4

eids <- sample(1:ecount(G), ecount(G)/2)
S1 <- subgraph.edges(G, eids)
S2 <- subgraph.edges(G, (1:ecount(G))[-eids])
E(S1)
# Edge sequence:
#           
# [1] 1 -> 5
# [2] 3 -> 2
# [3] 4 -> 2
# [4] 5 -> 4
E(S2)
# Edge sequence:
#           
# [1] 3 -> 1
# [2] 1 -> 3
# [3] 2 -> 3
# [4] 3 -> 5
# [5] 2 -> 4