Facebook Friendship Graph

facebook_friendship1.r

# the code uses 'facebook' function from the previous gist (https://gist.github.com/1634662) or 
# see the original http://romainfrancois.blog.free.fr/index.php?post/2012/01/15/Crawling-facebook-with-R

# scrape the list of friends
friends <- facebook( path="me/friends" , access_token=access_token)
# extract Facebook IDs
friends.id <- sapply(friends$data, function(x) x$id)
# extract names 
friends.name <- sapply(friends$data, function(x)  iconv(x$name,"UTF-8","ASCII//TRANSLIT"))
# short names to initials 
initials <- function(x) paste(substr(x,1,1), collapse="")
friends.initial <- sapply(strsplit(friends.name," "), initials) 

# friendship relation matrix
N <- length(friends.id)
friendship.matrix <- matrix(0,N,N)
for (i in 1:N) {
  tmp <- facebook( path=paste("me/mutualfriends", friends.id[i], sep="/") , access_token=access_token)
  mutualfriends <- sapply(tmp$data, function(x) x$id)
  friendship.matrix[i,friends.id %in% mutualfriends] <- 1
}

require(Rgraphviz)
# convert relation matrix to graph
g <- new("graphAM", adjMat=friendship.matrix)

# ellipse graph with initials
pdf(file="facebook1.pdf", width=25, height=25)
  attrs <- list(node=list(shape="ellipse", fixedsize=FALSE))
  nAttrs <- list(label=friends.initial)
  names(nAttrs$label) <- nodes(g)
  plot(g, "neato", attrs=attrs, nodeAttrs=nAttrs)
dev.off()