igraph delete_边的行为异常
我正在尝试从图形中删除边 我运行了以下代码igraph delete_边的行为异常,r,igraph,R,Igraph,我正在尝试从图形中删除边 我运行了以下代码 library(igraph) A <- c(0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,1,0,0,0,0) dim(A) <- c(5,5) g1 <- graph_from_adjacency_matrix(t(A), mode = c("directed")) g1 <- delete_edges(g1, c(1,2)) g1 <- simplify(g
library(igraph)
A <- c(0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,1,0,0,0,0)
dim(A) <- c(5,5)
g1 <- graph_from_adjacency_matrix(t(A), mode = c("directed"))
g1 <- delete_edges(g1, c(1,2))
g1 <- simplify(g1)
coords <- c(0.0, 0.951056, 0.587785, -0.587785, -0.951056,
1, 0.309017, -0.809017,-0.809017, 0.309017)
dim(coords) <- c(5,2)
plot(g1,
vertex.color=c(rgb(0,.5,.7),
rgb(.15,.6,0),
rgb(.5,.5,.5),
rgb(.8,.55,0),
rgb(.8,0,0)),
vertex.size = 20,
layout = coords,
main = paste("Graph", toString(1)))
库(igraph)
函数delete_edges
假定您正在传入边索引。你可以看到的边缘
E(g1)
# + 5/5 edges from faf79f6:
# [1] 1->2 2->3 3->4 4->5 5->1
因此,当您指定c(1,2)
时,您指定的是第一条边和第二条边,而不是从顶点1到2的边。如果你想这样做,你可以这样做
g1 <- delete_edges(g1, E(g1)[1 %--% 2])
这将删除从1到2以及从3到4的边。谢谢。如果允许的话,我会接受你的回答。添加边也是这样吗?不是。根据add_edges
的文档,您将传递一个“顶点数为偶数的顶点序列”。因此,add_-edges
需要一个顶点序列,而delete_-edges
需要一个边序列。另外,如果我想删除一个边列表呢。例如,如果我想删除边1->2和边3->4。我以为你会像g1@jd123那样写,我用一个可能的替代方法更新了它。
g1 <- g1 - edge("1|2")
g1 <- delete_edges(g1, E(g1, P=c(1,2,3,4)))