Black Lives Matter. Please consider donating to Black Girls Code today.
https://www.blackgirlscode.com/

Network Graph in R

How to make network graphs in R with Plotly.


New to Plotly?

Plotly is a free and open-source graphing library for R. We recommend you read our Getting Started guide for the latest installation or upgrade instructions, then move on to our Plotly Fundamentals tutorials or dive straight in to some Basic Charts tutorials.

Read Graph File

We are using the well-known social network of Zachary's karate club. GML format file can be collected from here.

library(plotly)
library(igraph)
library(igraphdata)

data(karate, package="igraphdata")
G <- upgrade_graph(karate)
L <- layout.circle(G)

Create Vertices and Edges

vs <- V(G)
es <- as.data.frame(get.edgelist(G))

Nv <- length(vs)
Ne <- length(es[1]$V1)

Create Nodes

library(plotly)

Xn <- L[,1]
Yn <- L[,2]

network <- plot_ly(x = ~Xn, y = ~Yn, mode = "markers", text = vs$label, hoverinfo = "text")

Creates Edges

edge_shapes <- list()
for(i in 1:Ne) {
  v0 <- es[i,]$V1
  v1 <- es[i,]$V2

  edge_shape = list(
    type = "line",
    line = list(color = "#030303", width = 0.3),
    x0 = Xn[v0],
    y0 = Yn[v0],
    x1 = Xn[v1],
    y1 = Yn[v1]
  )

  edge_shapes[[i]] <- edge_shape
}

Create Network

axis <- list(title = "", showgrid = FALSE, showticklabels = FALSE, zeroline = FALSE)

fig <- layout(
  network,
  title = 'Karate Network',
  shapes = edge_shapes,
  xaxis = axis,
  yaxis = axis
)

fig

Reference

See https://plotly.com/python/reference/#scatter for more information and chart attribute options!

What About Dash?

Dash for R is an open-source framework for building analytical applications, with no Javascript required, and it is tightly integrated with the Plotly graphing library.

Learn about how to install Dash for R at https://dashr.plot.ly/installation.

Everywhere in this page that you see fig, you can display the same figure in a Dash for R application by passing it to the figure argument of the Graph component from the built-in dashCoreComponents package like this:

library(plotly)

fig <- plot_ly() 
# fig <- fig %>% add_trace( ... )
# fig <- fig %>% layout( ... ) 

library(dash)
library(dashCoreComponents)
library(dashHtmlComponents)

app <- Dash$new()
app$layout(
    htmlDiv(
        list(
            dccGraph(figure=fig) 
        )
     )
)

app$run_server(debug=TRUE, dev_tools_hot_reload=FALSE)