Create pretty network-diagram of tweets with visjs, after custom filtering. (WORK IN PROGRESS)

gephi-2-igraph-2-visjs.R

# create pretty network-diagram of tweets,
# captured with Gephi's Twitter plugin,
# exported as JSON
# with more sophisticated filtering
# knbknb 20181209
library(visNetwork)
library(tidyverse)

workdir        <- "/home/knut/gephi/"
# infile created with "Export as ..." Feature of Gephi Desktop App
infile         <- "twitter-neurips2018--tweetnetwork.gephi.json"
outfile        <- paste0(workdir, infile, ".html")

gephi_json_str <- readr::read_file(file.path(workdir, infile))
# convert stringified JSON to R data structure
# (list of (sublists, data frames, empty data frames))
gephi_json     <- jsonlite::fromJSON(txt = gephi_json_str)
# gephi_json is a JSON object with 2 keys:
# {"nodes": [],  "edges": []}
# both are data frames with sublists
# str(gephi_json, max.level = 2) # long output
map_dbl(gephi_json, nrow) # number of elements
map_dbl(gephi_json, length) # number of attributes


nodes <- gephi_json$nodes %>%
        nest(attributes) %>%
        filter(str_detect(label, "@")) %>%
        select(id, label, size)
dim(nodes)

edges <- gephi_json$edges %>%
        rename("from" = source, "to"=target) %>%
        select(-attributes, -color)
dim(edges)
# edges2 <- edges %>% semi_join(nodes, by=c("to"="id") )
#g <- igraph::graph_from_data_frame(d= edges2, directed = TRUE,
#                                   vertices = nodes)
#summary(g)
#plot(g)



# enable_phys = FALSE:
# - much shorter rendering times even for larger graphs
# - layout is ugly
# enable_phys = TRUE:
# - startup + rendering time can be several minutes
# - layout is better (repulsion between nodes)
enable_phys <- TRUE

nw <- visNetwork::visNetwork(nodes = nodes, edges = edges,
                             width = 2000, height = 2000
                             ) %>%
        #visEdges(smooth = list(type="discrete", forceDirection="vertical")) %>%
        #visOptions(manipulation = FALSE) %>%
        visPhysics(enabled = enable_phys)

visNetwork::visSave(nw, outfile)
# open a web browser
browseURL(url = outfile, browser = "google-chrome")