NYT historical representation

require(quanteda)
require(ggplot2)

Representation of world threats

corp <- readRDS('Data/data_corpus_nytimes_summary.RDS')
toks <- tokens(corp)

dict <- dictionary(file = 'english.yml')
toks_dict <- tokens_lookup(toks, dict, level = 3)
mt_dict <- dfm(toks_dict)
mt_dict <- dfm_remove(mt_dict, 'us')

for (t in seq(1850, 2010, 10)) {
    mt_col <- fcm(mt_dict[floor(docvars(mt_dict, 'year') / 10) * 10 == t])
    size <- log(rowSums(mt_col) + 1)
    size <- size / max(size)
    plot <- textplot_network(mt_col, min_freq = 0.85, edge_size = 5, 
                             vertex_alpha = 0.8, vertex_size = size * 3)
    plot <- plot + ggtitle(paste0(t, 's'))
    print(plot)
}