删除igraph矢量上使用的顶点

Question

我正在尝试从igraph中的图形中删除顶点，但它无法正常工作。我认为这个问题可能与

有关

> toosmall <- which(V(g)$coreness.all <= 5)

因为它似乎返回整数（0）。

如何从下图中删除顶点？

> graph.coreness(g)
  [1]  1 19  1  3 17 19  5 19 19 19 19  7 19 18 17 12 12 19 19 17 16 19  3  3  7 12 18  4  5 12 12  3  1  6 19  5 19 19  3 19 17 17 19 19  5  1  1  7  8 19  1  2
  [53]  7  3 17  5  4 19  3 16  1  3 13  3 14 10 10 13  8 18 18 12  6 10 12 14 11 16 12  7  5  7  5 10 15 16 10  3  5  5 16 16 16 13 16 16 16 16 16 15 10  6  2  1
 [105] 14 16 16 11  5 11 16 11 10 16  2 14  7  8  1 10 12 12 12 19  8 10  7  5 13  3 19 16  3  4  4 19 13  7 16 13 11 13 15 13  3  2  3  3  2  9 14 16 16 14 16 13
 [157] 13 15 13 11 12 11  1  1 11 19  7  3 19  3  7  5 19 19 19 19 19 19 19 18 19 11 13 17  4 19 16 19 11  9  9 12 19 16 11 19  4  7  4 19  6  6  9  2 15  8  7  5
 [209] 10  7  3 10  6  8  4 11 13  2  7  6  7  6  9  4  3  3 13  3 13  9  4 13  5  5  6  6  6 14  8  2  5  7  7 14  7  9  6  8 12  1  1  1 14  1 10  8 16  2  6  9
 [261]  3  7 14 16 15  2  5  1  4  7 17  7  6  4 11  8  9 15  4  4 15  1  5  5  3  6  1  2  2  4  4  1  5  1  6  1  5  5  3  2  3  3  6  6  6  3  2  8  5  6  3  3
 [313]  2  1  5  2 12  3  1  6  1  2  5  2  1  3  1  1  8  2  3
> toosmall <- which(V(g)$coreness.all <= 5)
> delete.vertices(g,toosmall)
IGRAPH U--- 331 2771 -- 
+ attr: Color (v/c), Shape (v/c), Size (v/c), Opacity (v/c), Image File (v/c), Visibility (v/c), Label (v/c), Label Fill Color (v/c), Label
  Position (v/c), Tooltip (v/c), Layout Order (v/c), X (v/c), Y (v/c), Locked? (v/c), Polar R (v/c), Polar Angle (v/c), Degree (v/c), In-Degree
  (v/c), Out-Degree (v/c), Betweenness Centrality (v/c), Closeness Centrality (v/c), Eigenvector Centrality (v/c), PageRank (v/c), Clustering
  Coefficient (v/c), Reciprocated Vertex Pair Ratio (v/c), ID (v/c), Dynamic Filter (v/c), Add Your Own Columns Here (v/c), Followed (v/c),
  Followers (v/c), Tweets (v/c), Favorites (v/c), Time Zone UTC Offset (Seconds) (v/c), Description (v/c), Location (v/c), Web (v/c), Time Zone
  (v/c), Joined Twitter Date (UTC) (v/c), User of Interest? (v/c), Custom Menu Item Text (v/c), Custom Menu Item Action (v/c), id (v/c), Color
  (e/c), Width (e/c), Style (e/c), Opacity (e/c), Visibility (e/c), Label (e/c), Label Text Color (e/c), Label Font Size (e/c), Reciprocated?
  (e/c), ID (e/c), Dynamic Filter (e/c), Add Your Own Columns Here (e/c), Relationship (e/c), Relationship Date (UTC) (e/c), Tweet (e/c), URLs
  in Tweet (e/c), Domains in Tweet (e/c), Hashtags in Tweet (e/c), Tweet Date (UTC) (e/c), Twitter Page for Tweet (e/c), Latitude (e/c),
  Longitude (e/c), Imported ID (e/c), In-Reply-To Tweet ID (e/c), Edge Weight (e/c)
> g
IGRAPH U--- 331 2771 -- 
+ attr: Color (v/c), Shape (v/c), Size (v/c), Opacity (v/c), Image File (v/c), Visibility (v/c), Label (v/c), Label Fill Color (v/c), Label
  Position (v/c), Tooltip (v/c), Layout Order (v/c), X (v/c), Y (v/c), Locked? (v/c), Polar R (v/c), Polar Angle (v/c), Degree (v/c), In-Degree
  (v/c), Out-Degree (v/c), Betweenness Centrality (v/c), Closeness Centrality (v/c), Eigenvector Centrality (v/c), PageRank (v/c), Clustering
  Coefficient (v/c), Reciprocated Vertex Pair Ratio (v/c), ID (v/c), Dynamic Filter (v/c), Add Your Own Columns Here (v/c), Followed (v/c),
  Followers (v/c), Tweets (v/c), Favorites (v/c), Time Zone UTC Offset (Seconds) (v/c), Description (v/c), Location (v/c), Web (v/c), Time Zone
  (v/c), Joined Twitter Date (UTC) (v/c), User of Interest? (v/c), Custom Menu Item Text (v/c), Custom Menu Item Action (v/c), id (v/c), Color
  (e/c), Width (e/c), Style (e/c), Opacity (e/c), Visibility (e/c), Label (e/c), Label Text Color (e/c), Label Font Size (e/c), Reciprocated?
  (e/c), ID (e/c), Dynamic Filter (e/c), Add Your Own Columns Here (e/c), Relationship (e/c), Relationship Date (UTC) (e/c), Tweet (e/c), URLs
  in Tweet (e/c), Domains in Tweet (e/c), Hashtags in Tweet (e/c), Tweet Date (UTC) (e/c), Twitter Page for Tweet (e/c), Latitude (e/c),
  Longitude (e/c), Imported ID (e/c), In-Reply-To Tweet ID (e/c), Edge Weight (e/c)
> g <- delete.vertices(g,toosmall)
> g
IGRAPH U--- 331 2771 -- 
+ attr: Color (v/c), Shape (v/c), Size (v/c), Opacity (v/c), Image File (v/c), Visibility (v/c), Label (v/c), Label Fill Color (v/c), Label
  Position (v/c), Tooltip (v/c), Layout Order (v/c), X (v/c), Y (v/c), Locked? (v/c), Polar R (v/c), Polar Angle (v/c), Degree (v/c), In-Degree
  (v/c), Out-Degree (v/c), Betweenness Centrality (v/c), Closeness Centrality (v/c), Eigenvector Centrality (v/c), PageRank (v/c), Clustering
  Coefficient (v/c), Reciprocated Vertex Pair Ratio (v/c), ID (v/c), Dynamic Filter (v/c), Add Your Own Columns Here (v/c), Followed (v/c),
  Followers (v/c), Tweets (v/c), Favorites (v/c), Time Zone UTC Offset (Seconds) (v/c), Description (v/c), Location (v/c), Web (v/c), Time Zone
  (v/c), Joined Twitter Date (UTC) (v/c), User of Interest? (v/c), Custom Menu Item Text (v/c), Custom Menu Item Action (v/c), id (v/c), Color
  (e/c), Width (e/c), Style (e/c), Opacity (e/c), Visibility (e/c), Label (e/c), Label Text Color (e/c), Label Font Size (e/c), Reciprocated?
  (e/c), ID (e/c), Dynamic Filter (e/c), Add Your Own Columns Here (e/c), Relationship (e/c), Relationship Date (UTC) (e/c), Tweet (e/c), URLs
  in Tweet (e/c), Domains in Tweet (e/c), Hashtags in Tweet (e/c), Tweet Date (UTC) (e/c), Twitter Page for Tweet (e/c), Latitude (e/c),
  Longitude (e/c), Imported ID (e/c), In-Reply-To Tweet ID (e/c), Edge Weight (e/c)
> toosmall
integer(0)

Answer 1

我认为您必须将toosmall定义为：

toosmall <- which(graph.coreness(g) <= 5)

这是一个使用构造图的工作示例，其中我使用较低的阈值作为删除标准：

# Create a graph
g <- graph.ring(10)
g <- add.edges(g, c(1,2, 2,3, 1,3))
graph.coreness(g)

# Identify vertices with coresness <= threshold
toosmall <- which(graph.coreness(g) <= 2)

# Delete vertices and plot
gp <- delete.vertices(g, toosmall)
plot(gp)