Adding a legend in visNetwork for edge color

问题

I am using visNetwork to visualize a graph, but I need to introduce a legend based on the edge color. edge color is dependent on an edge attribute and its dynamic in nature. I tried to do with visGroups/visLegend, but got multiple errors. PFB reproducible example.

    library(igraph)
    library(visNetwork)
    gg <- graph.atlas(711)
    V(gg)$name=1:7
    gg=set_edge_attr(gg,"Department",E(gg)[1:10],c("A","B","C","A","E","C","G","B","C","A"))
    E(gg)$label=E(gg)$Department
    F2 <- colorRampPalette(c("red", "blue","orange","violet","cyan"), bias = length(unique(E(gg)$Department)), space = "rgb", interpolate = "linear")
    colCodes <- F2(length(unique(E(gg)$Department)))
    edges_col <- sapply(E(gg)$Department,function(x) colCodes[which(sort(unique(E(gg)$Department)) == x)])
    E(gg)$color <-edges_col
    datatest = toVisNetworkData(gg)
    visNetwork(datatest$nodes,datatest$edges) %>% visIgraphLayout(layout="layout_in_circle") 

I need legends as Red - A , Blue - C etc.

Kindly help.

回答1:

visLegend is first based on nodes groups, but you can also set nodes and/or edges legend manually. (?visLegend)

For you for example :

# data.frame from edges legend
ledges <- data.frame(color = unique(edges_col), 
                     label = unique(names(edges_col))) 

visNetwork(datatest$nodes,datatest$edges) %>% visIgraphLayout(layout="layout_in_circle") %>%
  visLegend(useGroups = F, addEdges = ledges)

来源：https://stackoverflow.com/questions/38602251/adding-a-legend-in-visnetwork-for-edge-color