Extract an induced temporal subgraph

Usage

induce_subgraph(dn, nodes = NULL, ties = NULL, keep_isolates = FALSE)

Arguments

dn: A temporal network.
nodes: Which vertices to keep. Either a condition on the vertex table, evaluated the way subset() evaluates one – degree > 20, room == "A" & betweenness > 0 – with any centrality it names computed over the whole observed period; or a character vector of names, a factor, a logical mask, or any data frame carrying a name or node column. Only ties whose two endpoints are in this set are eligible. Default NULL, meaning every vertex.
ties: Which ties to keep. Either a condition on the spell table, evaluated the way subset() evaluates one – course == "g1", duration > 2 & weight >= 1 – over the columns as.data.frame(dn) returns, tie attributes included; or integer row positions or a logical mask over that same table, in that order, a mask having exactly as many elements as there are spells. Default NULL, meaning every tie. At least one of nodes and ties must be supplied.
keep_isolates: Whether named nodes without a selected tie remain. Default FALSE; it has an effect only when nodes is supplied.

Value

A new dynet object, class c("dynet", "netobject", "cograph_network"), carrying only the selected spells, the vertices they touch (plus any isolate named in nodes when keep_isolates = TRUE), those vertices' activity spells, and all static node and tie attributes. Metadata is rebuilt, so the observed range and the canonical spell identifiers describe the subgraph, not the parent. Raises dynet_unknown_node for a name that is not a vertex, dynet_empty_network when the selection leaves no vertex or no tie, and dynet_bad_input when neither nodes nor ties is supplied or a selection is malformed.

Examples

dn <- dynet(school_contacts)

# A condition on the vertex table, in one call.
induce_subgraph(dn, degree > 16)
#> # Temporal network (interval format, directed) | a cograph netobject
#> # 5 vertices | 31 edge spells | 14 distinct pairs
#> # observed from 0 to 20.46 step, binned every 1
#> 
#>   from    to start  end duration weight
#>  Jonas   Dan  0.00 1.10     1.10      1
#>    Eve  Kira  0.77 1.42     0.65      1
#>   Kira   Eve  1.95 2.47     0.52      1
#>  Jonas  Kira  2.05 2.09     0.04      1
#>    Dan Jonas  3.14 3.49     0.35      1
#>    Dan   Eve  3.20 3.33     0.13      1
#> # 25 more spells. summary() describes the network; plot() draws it.

# Names still work, as does anything carrying them.
induce_subgraph(dn, nodes = c("Ana", "Ben", "Cara"))
#> # Temporal network (interval format, directed) | a cograph netobject
#> # 3 vertices | 3 edge spells | 3 distinct pairs
#> # observed from 6.67 to 20.33 step, binned every 1
#> 
#>  from   to start   end duration weight
#>   Ana Cara  6.67  6.77     0.10      1
#>  Cara  Ben 16.84 17.09     0.25      1
#>  Cara  Ana 19.70 20.33     0.63      1