Choose most efficient format heuristically — choose

Given a graph suggest the most efficient format out of 'graph6', 'sparse6' or 'digraph6'.

Usage

choose_format(object, ...)

# Default S3 method
choose_format(object, ...)

# S3 method for class 'list'
choose_format(object, ...)

Arguments

object: Igraph/network object or list thereof
...: other arguments, currently ignored

Value

Character value out of 'graph6', 'sparse6' or 'digraph6'. If object is a list, a vector of such values of the length equal to the length of object.

Details

If object is directed, the suggested format is 'digraph6'. If object is undirected the function suggests 'sparse6' if density is less than 0.15 and 'graph6' otherwise. This rule is approximate.

Examples

# From igraph ------------------------------------------------------
if(requireNamespace("igraph")) {
   g <- igraph::graph.famous("Zachary")
   choose_format(g)
   
   set.seed(123)
   glist <- list(
      igraph::sample_gnp(n = 15, p = 0.1),
      igraph::sample_gnp(n = 15, p = 0.2), 
      igraph::sample_gnp(n = 15, p = 0.3),
      igraph::sample_gnp(n = 15, p = 0.15, directed = TRUE))
      
   choose_format(glist)
}
#> [[1]]
#> [1] "sparse6"
#> 
#> [[2]]
#> [1] "graph6"
#> 
#> [[3]]
#> [1] "graph6"
#> 
#> [[4]]
#> [1] "digraph6"
#> 

# From network -----------------------------------------------------
if(requireNamespace("network")) {
   m <- matrix(rbinom(25,1,.4),15,15)
   diag(m) <- 0
   g <- network::network(m, directed=FALSE)
   choose_format(g)
}
#> [1] "graph6"