visNetwork R：指定变量节点背景颜色和边框颜色

Question

I would like to be able to vary the background colour of the nodes in my graph, and also use a border colour to ensure nicely marked-out nodes compared to edges.

I thought that the following should work, but it does not:

nodes <- data.frame(id = 1:3,
                    color = c("lightblue","red","blue"))
edges <- data.frame(from = c(1,2), to = c(1,3))
visNetwork(nodes, edges) %>% visNodes(color = list(border = "black"))

Resultant network

I tried providing a vector of colors directly to visNodes, which failed. Indeed the colors are retained from the data.frame column color

visNetwork(nodes, edges) %>% visNodes(color = list(background = c("yellow","pink","blue"), 
border = "black"))

Resultant network

visNetwork is a great package but is under queried on StackOverflow.

I'm posting this here on behalf of Charlie from GitHub after asking for due permission, primarily to have this available on StackOverflow for other R viz enthusiasts to get their answers here.

I had to post hyperlinks to pictures since I'm new to StackOverflow with a profile (Have used it for years as an Analytics Consultant, but didn't think about creating a profile, didn't know the use for it) and am not allowed to post images before collecting 10 reputation points.

Answer 1

This case is interesting. First, we can pass individual options to nodes/edges data.frame, and global option for all nodes / edges with visNodes and visEdges.

So you can't do that:

visNetwork(nodes, edges) %>% visNodes(color = list(background = c("yellow","pink","blue"), 
border = "black"))

But just assign one background and border color with this way:

visNetwork(nodes, edges) %>% visNodes(color = list(background = "blue", 
border = "black"))

color can be a simple option with one value, or have a more complex definition. In your first example, it seems that the definition of color in data.frame overwrite the visNodes options.

Since 0.2.1, you can now pass complex options (list) directly in data.frame like this:

nodes <- data.frame(id = 1:3,
                    color.background = c("lightblue","red","blue"),
                    color.border = "black")
edges <- data.frame(from = c(1,2), to = c(1,3))
visNetwork(nodes, edges)

and so:

nodes <- data.frame(id = 1:3,
                    color.background = c("lightblue","red","blue"))
edges <- data.frame(from = c(1,2), to = c(1,3))
visNetwork(nodes, edges) %>% visNodes(color = list(border = "black"))

PS: Posting an answer myself since this conversation was available on GitHub issues already. Just wanted to document it here for the community's ease.