R/sub_groups.R

In XPHenry/Netfrac: Netfrac - Community distance calculation within sequence similarity networks

#========================================
#= creates subgraph or 2 groups from a complex graph
#========================================
#assuming that we already have an igragh object with group information
#' Creates a subgraph based on chosen species communities
#'
#' Creates another igraph object containing only the nodes from some chosen species
#' communities (two or more), and the edges connecting them.
#'
#' @param graph The igraph object
#' @param groups The communities that should be isolated, indicated as a list of two items
#'
#' @return
#' @export
#'
#' @examples
#' CAT_env1 <- set_color(subgroup_graph(CAT_env, c("host", "ubiquitous")))
#' plot(CAT_env1)
subgroup_graph <- function(graph, groups){
  subvertice <- V(graph)[V(graph)$tax %in% groups]
  graph <- induced.subgraph(graph, subvertice)
  return (graph)
}