Plotting

Plotting

Plotting in snafun

The snafun package provides a plot(x) function, which allows the user to make a quick plot of a network, regardless of whether x is a graph of class network or igraph. This function wraps network::plot.network and igraph::plot.igraph and will use the default settings of these functions.

However, one can also use all of the arguments from network::plot.network and igraph::plot.igraph to make the plots nicer when wanted.

Here is an example for a network object.

g_n <- snafun::create_random_graph(10, "gnm", m = 20, graph = "network")
snafun::plot(g_n)

snafun::plot(g_n, vertex.cex = 3, vertex.col = "green", edge.lwd = 10, 
  edge.col = "darkgrey", usecurve = TRUE, edge.curve = .05, 
  arrowhead.cex = 3, displaylabels = TRUE, label.pos = 5)

And for an igraph graph object:

g_i <- snafun::create_random_graph(10, "gnm", m = 20, graph = "igraph")
snafun::plot(g_i)

snafun::plot(g_i, vertex.size = 12, vertex.color = "green", edge.width = 5, edge.curved = TRUE)

The most common use case for the function is to make as quick plot of the network, using default settings, as one usually would do in the initial phase of a study. For this, snafun provides a consistent function name.

The snafun package also contains a function to plot centrality scores of the vertices. The function and its options are specified as follows:

snafun::plot_centralities(
  net,
  measures = c("betweenness", "closeness", "degree", "eccentricity"),
  directed = TRUE,
  mode = c("all", "out", "in"),
  k = 3,
  rescaled = FALSE,
  ...
)

This yields a plot like this:

The function takes an object of class igraph or network and plots the centrality scores you select, so you can visually compare them. Make sure to pick the required value for mode (the default is “all”).

Basic plotting in igraph

The plot function alone already plots nodes and edges with default options. More sophisticated specifications need to be manually set. It works with networks of class igraph.

igraph::plot.igraph(net,
     edge.arrow.size = .2,                # edge and arrow size
     edge.color = "red",                  # edge color
     vertex.color = "blue",               # vertex filling color
     vertex.frame.color = "green",        # vertex perimeter color
     vertex.label = igraph::V(net)$label, # vertex labels
     vertex.label.cex = 0.6,              # vertex label size
     vertex.label.color = "black")        # vertex label color

Basic plotting in network

The gplot function alone already plots nodes and edges with default options. More sophisticated specifications need to be manually set. It works with networks of class network.

network::plot.network(net,
      arrowhead.cex = 0.2,     # edge and arrow size
      edge.col = 'red',        # edge color
      vertex.col = 'blue',     # vertex filling color
      vertex.border = 'green', # vertex perimeter color
      displaylabels = TRUE,    # vertex labels
      label.cex = 0.6,         # vertex label size
      label.col = 'black')     # vertex label color

Basic plotting in sna

The gplot function alone already plots nodes and edges with default options. More sophisticated specifications need to be manually set. It works with networks of class network.

sna::gplot(net,
      arrowhead.cex = 0.2,     # edge and arrow size
      edge.col = 'red',        # edge color
      vertex.col = 'blue',     # vertex filling color
      vertex.border = 'green', # vertex perimeter color
      displaylabels = TRUE,    # vertex labels
      label.cex = 0.6,         # vertex label size
      label.col = 'black')     # vertex label color

The gplot function has a few additional arguments compared to network::plot.network and is therefore slightly more flexible.