rpubmed (version 0.1)

mesh_assoc_table: Builds an association matrix for all MeSH terms in an article corpus

Description

Builds an association matrix for all MeSH terms in an article corpus

Usage

mesh_assoc_table(corpus)

Arguments

corpus

a list of Pubmed records. e.g. as returned by fetch_in_chunks()

Value

matrix

Examples

## Not run: 
# 
# articles <- fromJSON("Test/PCD_articles.json")
# diab = get_articles_by_terms(articles, list("diabetes", c("case-control")), where= in_mesh_abstract_p)
# diab_assoc <- mesh_assoc_table(diab)
# # list of MeSH headings with frequencies:
# d <- diag(diab_assoc)
# 
# Pick only those appearing in > 5 articles:
# d_5 <- d[d > 5]
# # Reduce assoc table to those with > 5 articles:
# diab_5 <- diab_assoc[names(d_5), names(d_5)]
# 
# # Graph the results:
# require(igraph)
# g <- graph.adjacency(diab_5, mode = "upper", weighted = TRUE)
# g <- simplify(g)
# V(g)$label <- V(g)$name
# V(g)$degree <- degree(g)
# layout1 <- layout.fruchterman.reingold(g)
# V(g)$label.cex <- V(g)$degree / max(V(g)$degree)
# plot(g, layout=layout1)
# ## End(Not run)