R中的着色图连接

Question

我在R中构建了一个图形，我成功地使用if语句在颜色上着色一些顶点，我使用tkplot函数来获得更好的可视化。
现在我有以下图表：

FROM    TO  
A   B
A   D
B   C
B   F
D   E
E   G
E   H
H   M
H   L
L   N

和以下顶点集

E  
L

我需要绘制图表着色连接传入和输出在E和L中的红色，而所有其他在黑色中。
为了清楚起见，我需要红色以下连接线

FROM    TO
D   E
E   G
E   H
H   L
H   M

有解决方案吗？

Answer 1

只需使用您想要的颜色创建一个颜色矢量，对应B中的边缘：

library(igraph) 
B = matrix( c("A" ,"A", "B" ,"B","D","E", "E", "H", "H", "L", "B","D","C","F","E","G","H","M","L","N"), ncol=2) 
B<- data.frame(B) 
grf<- graph.data.frame (B, directed =TRUE, vertices=NULL) 
error<-array(c("E", "L")) 
V(grf)$color <- ifelse(V(grf)$name %in% error, "red", "yellow") 

col = rep("black", nrow(B)) 
col[B$X1 == "E" | B$X2 == "L"] <- "red" 
# or 
# col[B$X1 %in% c("E", "L") | B$X2 %in% c("E", "L")] <- "red" 
plot(grf, edge.color = col)
# or     
# tkplot(grf, edge.color = col)

Answer 2

使用edge.color属性不是唯一的方法。 您还可以为每个边缘设置color属性，例如：
（可以找到有关V(g)和E(g)函数的更多信息here）

library(igraph)

# initialize the graph
DF <- 
read.table(text=
"FROM TO  
A B
A D
B C
B F
D E
E G
E H
H M
H L
L N",header=T,stringsAsFactors=T)
g <- graph.data.frame(DF)

# set a color (black) attribute on all edges
E(g)$color <- 'black'
# set red color for the edges that have an incident vertex in the set 'E,L'
nodesSeq <- V(g)[name %in% c('E','L')]
E(g)[inc(nodesSeq)]$color <- 'red'

tkplot(g)