ggnet.Rmd

---
title: "ggplot2 extensions: ggnet"
---

### ggnet
<https://github.com/briatte/ggnet>

The *ggnet2* function is a visualization function to plot network objects as **ggplot2** objects. It accepts any object that can be coerced to the **network** class, including adjacency or incidence matrices, edge lists, or one-mode **igraph** network objects.

```{r, message=FALSE,warning=FALSE}
# Example from http://briatte.github.io/ggnet/
library(ggplot2)
library(ggnet)
library(ggnetwork)

# Let’s define a small random graph to illustrate each component of ggnetwork:
library(network)
library(sna)
n = network(rgraph(10, tprob = 0.2), directed = FALSE)

# Let’s now add categorical and continuous attributes for both edges and vertices
n %v% "family" = sample(letters[1:3], 10, replace = TRUE)
n %v% "importance" = sample(1:3, 10, replace = TRUE)

# We now add a categorical edge attribute called "type", 
# which is set to either "x", "y" or "z", and a continuous vertex 
# attribute called "day", which is set to either 1, 2 or 3.
e = network.edgecount(n)
set.edge.attribute(n, "type", sample(letters[24:26], e, replace = TRUE))
set.edge.attribute(n, "day", sample(1:3, e, replace = TRUE))

# Let’s now draw the network edges using geom_edges
# theme_blank
ggplot(data = ggnetwork(n), aes(x = x, y = y, xend = xend, yend = yend)) +
  geom_edges(aes(linetype = type), color = "grey50") +
  theme_blank()

# Let’s now draw the nodes using geom_nodes
ggplot(data = ggnetwork(n), aes(x = x, y = y, xend = xend, yend = yend)) +
  geom_edges(aes(linetype = type), color = "grey50") +
  geom_nodes(aes(color = family, size = importance)) +
  theme_blank()

# Let’s now add node labels.
ggplot(data = ggnetwork(n), aes(x = x, y = y, xend = xend, yend = yend)) +
  geom_edges(color = "black") +
  geom_nodes(color = "black", size = 8) +
  geom_nodetext(aes(color = family, label = LETTERS[ vertex.names ]), fontface = "bold") +
  theme_blank()
```