Union of igraph objects loses attributes

Question

I have two igraph objects, which have different color attributes. Vertices \"A\" and \"B\" in first graph are colored red. Vertices <

Answer 1

igraph doesn't loose the colors, it stores them in $color_1 and $color_2. I think this is because in the general case there might be common vertices with different colors. What would you do then?

Try this:

V(graph)$color <- ifelse(is.na(V(graph)$color_1),
                         V(graph)$color_2,V(graph)$color_1)
plot(graph)

BTW: your code didn't run for me. I had to use:

graph <- graph.union(graph.1, graph.2, byname=T)