A graph for TDA's graph commands

A graph for TDA's graph commands

Usage

tda_graph(
  edges,
  directed = TRUE,
  form = c("edges", "dissimilarity"),
  options = list()
)

Arguments

edges

an edge list – from, to, and one value, or two values when the graph carries a different one in each direction, as the shipped gd1.dat does – or a square adjacency matrix, or a dist.

directed

whether the graph is directed. FALSE emits gt=2. Several commands – tda_g_components among them, and plot.tda_graph's layout = "tree" – only work on an undirected graph, and TDA itself refuses a directed one for them; directed = TRUE (the default here) is right for ordinary, arrow-drawn graphs, but a tree needs FALSE, since a tree's layout comes from which nodes are connected, not which way an edge happens to point.

form

how TDA is to read it: "edges" for an edge list, which is gdd option 1, or "dissimilarity" for the upper triangle of a dissimilarity matrix, option 4.

options

a named list of further gdd options.

Value

A tda_graph.

See also

Other graph analysis: plot.tda_graph(), tda_dmet(), tda_g(), tda_g_analyses, tda_locate_line(), tda_ptree(), tda_ucl()

Examples

e <- data.frame(from = c(1, 1, 2, 3), to = c(2, 3, 4, 4), value = 1)
# gcon works on an undirected graph only, so `directed = FALSE`
tda_g_components(tda_graph(e, directed = FALSE))
#> Call: tda_g_components(tda_graph(e, directed = FALSE))
#> 
#> Cases: 4 
#> 
#>  component n i node_i
#>          1 4 1      1
#>          1 4 2      2
#>          1 4 3      3
#>          1 4 4      4