Animating graph over time

animate.R

library(ggraph)
library(gganimate)
library(igraph)
# Data from http://konect.uni-koblenz.de/networks/sociopatterns-infectious
infect <- read.table('out.sociopatterns-infectious', skip = 2, sep = ' ', stringsAsFactors = FALSE)
infect$V3 <- NULL
names(infect) <- c('from', 'to', 'time')
infect$timebins <- as.numeric(cut(infect$time, breaks = 100))

# We want that nice fading effect so we need to add extra data for the trailing
infectAnim <- lapply(1:10, function(i) {infect$timebins  <- infect$timebins + i; infect$delay <- i; infect})
infect$delay <- 0
infectAnim <- rbind(infect, do.call(rbind, infectAnim))

infectGraph <- graph_from_data_frame(infectAnim, directed = F)

# We use only original data for the layout
subGr <- subgraph.edges(infectGraph, which(E(infectGraph)$delay == 0))
V(subGr)$degree <- degree(subGr)
lay <- createLayout(subGr, 'igraph', algorithm = 'lgl')

# Then we reassign the full graph with edge trails
attr(lay, 'graph') <- infectGraph

# Now we create the graph with timebins as frame
p <- ggraph(data = lay) + 
  geom_node_point(aes(size = degree), colour = '#8b4836') + 
  geom_edge_link0(aes(frame = timebins, alpha = delay, width = delay), edge_colour = '#dccf9f') + 
  scale_edge_alpha(range = c(1, 0), guide = 'none') + 
  scale_edge_width(range = c(0.5, 1.5), trans = 'exp', guide = 'none') + 
  scale_size(guide = 'none') + 
  ggtitle('Human Interactions') +
  ggforce::theme_no_axes() + 
  theme(plot.background = element_rect(fill = '#1d243a'), 
        panel.background = element_blank(), 
        panel.border = element_blank(), 
        plot.title = element_text(color = '#cecece'))

# And then we animate
animation::ani.options(interval=0.1)
gg_animate(p, 'animation.gif', title_frame = FALSE)

thanks for this - I am having one issue at the moment. In the plot, the line - geom_edge_link0(aes(frame = timebins, alpha = delay, width = delay), edge_colour = '#dccf9f') - it seems to me that these variables are not in the dataframe lay. Should they have a data=infectAnim argument- otherwise how will ggplot know where to find them?

Ah, I think I get it. lay inherits the info from infectGraph - thanks

I get this error, I do not know why:
Error in create_layout(graph, layout, ...) :
argument "graph" is missing, with no default