visNetwork in R

Question

I am creating a visualization using visNetwork in I want someone here help me with step by step process of creating the visualization in R. How can I create a visualization of 20 nodes with edges linking them. Thank you

Answer 1

visNetwork relies on data frames to indicate the node name and id, as well as the edges connected to the node in question. A minimal example of 20 nodes is as follows:

library(shiny)
library(visNetwork)

nodes <- data.frame(id = 1:20, label = 1:20)
edges <- data.frame(from = c(1:20), to = c(2:20,1))

server <- function(input, output, session) {
  output$myNetId <- renderVisNetwork({
    visNetwork(nodes, edges)
    })
}

ui <- fluidPage(
  visNetworkOutput("myNetId",
                   height <- "400px",
                   width <- "600")
)

shinyApp(ui <- ui, server <- server)

Going step by step, after importing the two libraries required we then specify the node data.frame which can include a label variable if you want text to populate next to the node. We've just specified 20 nodes going from 1 to 20.

the edges variable represents an edge list, with each line in the data.frame representing a start and end point for a single edge. A data.frame that looks like:

data.frame(from = c(1,1), to = c(2,3))

... Would produce two edges from node #1 to node #2 and #3. I've set it up so each node connects to the next sequential node like a circle.

The server is a shinyApp object that uses "myNetId" as a reference to how the visNetwork should operate, while the visNetworkOutput() function in the ui acts as a canvas indicating where in the screen the network should display. You can add additional parameters to the visNetwork() function using >%> as follows:

  visNetwork(nodes, edges) %>%
      visPhysics(solver = "barnesHut",
                 minVelocity = 0.1,
                 forceAtlas2Based = list(gravitationalConstant = -150)) %>%
      visOptions(manipulation = TRUE, highlightNearest = FALSE) %>%
      visEdges(arrows = 'to')

Hope that helps!