Q:

colouring graph connections in R

I built in R a graph and I succeeded in colouring some vertex using if statement in colour, i used the tkplot function to have a better visualization.
Now I have the following graph:  
FROM    TO  
A   B
A   D
B   C
B   F
D   E
E   G
E   H
H   M
H   L
L   N

and the following vertex set 
E  
L

I need to plot the graph coloring the connection incoming and outcoming in E and L in RED colour while all the other in BLACK.
To be clear I need in red the following connections lines
FROM    TO
D   E
E   G
E   H
H   L
H   M

Is there a solution for this? 

A:

Using edge.color property isn't the only way. 
You can also set a color attribute to each edge, e.g. :
(more informations about V(g) and E(g) functions can be found 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)

