Community detection with bipartite graph in igraph - igraph

Question

I have bipartite list (posts, word categories) with 1000 vertecies and want to use the fast and greedy algorithm for community detection, but I am not sure if I have to run it on the bipartite graph or the bipartite projection.
My bipartite list looks like this:
post word
1 66 2
2 312 1
3 432 7
4 433 7
5 434 1
6 435 5
7 436 1
8 437 4
When I run it without a projection I have problems clustering in the second step:
### Load bipartie list and create graph ###
bipartite_list <- read.csv("bipartite_list_tnf.csv", header = TRUE, sep = ";")
bipartite_graph <- graph.incidence(bipartite_list)
g<-bipartite_graph
fc <- fastgreedy.community(g) ## communities / clusters
set.seed(123)
l <- layout.fruchterman.reingold(g, niter=1000, coolexp=0.5) ## layout
membership(fc)
# 2. checking who is in each cluster
cl <- data.frame(name = fc$post, cluster = fc$membership, stringsAsFactors=F)
cl <- cl[order(cl$cluster),]
cl[cl$cluster==1,]
# 3. preparing data for plot
d <- data.frame(l); names(d) <- c("x", "y")
d$cluster <- factor(fc$membership)
# 4. plot with only nodes, colored by cluster
p <- ggplot(d, aes(x=x, y=y, color=cluster))
pq <- p + geom_point()
pq
Maybe I have to run the communnity detection on a projection? But then I always get I failure because a projection is not a graph object:
bipartite_graph <- graph.incidence(bipartite_list)
#projection (both directions)
projection_word_post <- bipartite.projection(bipartite_graph)
fc <- fastgreedy.community(projection_word_post)
Fehler in fastgreedy.community(projection_word_post) : Not a graph object
I would be glad for help!

Answer 1

When you run without the projection the issue is at:
bipartite_graph <- graph.incidence(bipartite_list)
You need to reshape 'bipartite_list' before applying into graph.incidence() function. Use the below command
tab <- table(bipartite_list)
and rest of the steps are same
g <- graph.incidence(tab,mode=c("all"))
fc <- fastgreedy.community(g)