有权重的最小生成树

Question

起初我想为我的研究制作一棵最大生成树，但我发现考虑到我在 R 中的时间和知识，它会太复杂。

所以我的选择是通过反转数据的顺序来创建最小生成树。事实上，处理从 1 到 3 的序数数据时，我只需要颠倒数据库中的顺序即可。

我在这里找到了对我有很大帮助的语法：https://web.stanford.edu/class/bios221/book/Chap-Graphs.html#minimum-spanning-trees 我做了必要的调整以获得图表。但是我不能在这张图上加权重...

这是我想要达到的目标：获得最小生成树，每个点之间的权重没有节点标题重叠，并且节点在图中正确拟合。

以下是我不能做和不明白的事情：

排斥命令不起作用，我不明白为什么。 R 告诉我这个命令是未知的。我插入：geom_node_text(aes(label = name), repel = TRUE。它不会使命令出现问题。我真的不明白为什么

权重：我试过：graph.adjacency(mstree, mode = "undirected",weight=TRUE) 显然我把权重设置为 true 或 false 它不会改变任何东西。再一次，我一定是错过了什么

我试着举了一个尽可能接近我的问题的例子。（这是我第一次发布示例，希望我做对了）：

library(dplyr)
library(igraph)
library(ape)
library(tidyr)
library(ggplot2)
library(ggnetwork)
library(ggraph)

M1 <- as_tibble(replicate(21,sample(1:3,100,rep=TRUE)))
colnames(M1) <- c("1st", "2nd", "3th", "4th", "5th", "6th","7th","8th","9th","10th",
                          "11th","12th","13th","14th","15th","16th","17th","18th","19th",
                          "20th","21th")

M2 <- as.matrix(round(cor(M1[,],method ="kendall"),2))

mstree <- ape::mst(M2)
gr4ph <-  graph.adjacency(mstree, mode = "undirected",weight=TRUE)
gg <-  ggnetwork(gr4ph, arrow.gap = 0, layout = layout_with_fr(gr4ph))
ggplot(gg, aes(x = x, y = y, xend = xend, yend = yend)) +
  geom_edges(color = "black", alpha = 1, curvature = 0.1) +
  geom_nodes(aes(color = name), size = 6) +  theme_blank() +
  geom_nodetext(aes(label = name), color = "black", size = 3.5) +
  theme(plot.margin = unit(c(0, 1, 2, 4), "cm"))+
  guides(color = guide_legend(keyheight = 0.09, keywidth = 0.09,
                              title = "Mots")) + theme(legend.position = c(-0.05, 0.14),
                                                       legend.background = element_blank(),
                                                       legend.text = element_text(size = 7))

感谢您的帮助

Answer 1

igraph doc page 有一个名为 weighted 的参数，它有效。

# weighted
n1 <- igraph::graph.adjacency(mstree, mode = "undirected", weighted = TRUE)
E(n1)$weight # 1 1 1 1 etc.

# unweighted
n2 <- igraph::graph.adjacency(mstree, mode = "undirected", weighted = NULL)
E(n2)$weight # NULL

有权重的最小生成树

Minimum spanning trees with weight

r

graph-theory

minimum-spanning-tree

weighted-graph