Build a direct citation network

Constructs a directed citation network from the references table of an sm_corpus. Each node represents a work and a directed edge runs from the citing work to the cited work. Only works present in the corpus (i.e. both the citing and cited work exist in corpus$works) are included as nodes unless external references are also present via cited_work_id.

Usage

sm_network_citation(corpus, call = rlang::caller_env())

Arguments

corpus

An sm_corpus object. Must contain a non-empty references table with columns work_id and cited_work_id.

call

Caller environment for error reporting.

Value

A tidygraph::tbl_graph object (directed). Node data contains name (the work ID) plus any columns from corpus$works. Edge data contains from, to, and any additional reference metadata.

Details

Empty input (zero works or zero references) returns an empty directed tbl_graph with a single name column on nodes and no edges.

See also

Other networks: sm_network_cocitation(), sm_network_collab(), sm_network_coupling(), sm_network_coword(), sm_network_semantic()

Examples

corpus <- sm_example_corpus()
g <- sm_network_citation(corpus)
g
#> # A tbl_graph: 200 nodes and 1869 edges
#> #
#> # A bipartite simple graph with 1 component
#> #
#> # Node Data: 200 × 16 (active)
#>    name      doi   title abstract  year type  source_id cited_by_count oa_status
#>    <chr>     <chr> <chr> <chr>    <int> <chr> <chr>              <int> <chr>    
#>  1 W0000000… 10.1… Tumo… This st…  2023 jour… S0000000…              3 green    
#>  2 W0000000… 10.1… Biom… This st…  2020 jour… S0000000…              9 hybrid   
#>  3 W0000000… 10.1… Colo… This st…  2024 jour… S0000000…             28 green    
#>  4 W0000000… 10.1… Tumo… This st…  2020 revi… S0000000…             29 green    
#>  5 W0000000… 10.1… Clin… This st…  2020 jour… S0000000…             16 hybrid   
#>  6 W0000000… 10.1… Tumo… This st…  2018 jour… S0000000…             16 closed   
#>  7 W0000000… 10.1… Sing… This st…  2021 lett… S0000000…             26 bronze   
#>  8 W0000000… 10.1… Colo… This st…  2020 jour… S0000000…              7 hybrid   
#>  9 W0000000… 10.1… Gene… This st…  2024 revi… S0000000…              6 gold     
#> 10 W0000000… 10.1… Colo… This st…  2019 revi… S0000000…              5 gold     
#> # ℹ 190 more rows
#> # ℹ 7 more variables: language <chr>, pmid <chr>, arxiv_id <chr>,
#> #   openalex_id <chr>, is_retracted <lgl>, retraction_date <date>,
#> #   last_refreshed <dttm>
#> #
#> # Edge Data: 1,869 × 2
#>    from    to
#>   <int> <int>
#> 1     1     9
#> 2     1     7
#> 3     1    47
#> # ℹ 1,866 more rows