R/get_graph_series_info.R

In DiagrammeR: Graph/Network Visualization

#' Get information on a graph series
#'
#' @description
#'
#' Obtain a data frame with information on the graphs within a graph series.
#'
#' @param graph_series A graph series object of type `dgr_graph_1D`.
#'
#' @return A data frame containing information on the graphs within the supplied
#'   graph series.
#'
#' @examples
#' # Create three graphs
#' graph_1 <-
#'   create_graph() %>%
#'   add_path(n = 4)
#'
#' graph_2 <-
#'   create_graph() %>%
#'   add_cycle(n = 5)
#'
#' graph_3 <-
#'   create_graph() %>%
#'   add_star(n = 6)
#'
#' # Create an empty graph series
#' # and add the graphs
#' series <-
#'   create_graph_series() %>%
#'   add_graph_to_graph_series(
#'     graph = graph_1) %>%
#'   add_graph_to_graph_series(
#'     graph = graph_2) %>%
#'   add_graph_to_graph_series(
#'     graph = graph_3)
#'
#' # Get information on the graphs in the series
#' series %>% get_graph_series_info()
#'
#' @export
get_graph_series_info <- function(graph_series) {

  graphs_in_series <-
    count_graphs_in_graph_series(graph_series)

  series_info_df <-
    dplyr::tibble(
      graph = integer(0),
      name = character(0),
      date_time = Sys.time(),
      tz = character(0),
      nodes = integer(0),
      edges = integer(0),
      directed = logical(0)
    ) %>%
    as.data.frame(stringsAsFactors = FALSE)

  if (graphs_in_series == 0) {
    return(series_info_df)
  }

  for (i in 1:graphs_in_series) {

    # Add a graph index number
    series_info_df[i, 1] <- i

    # Add the graph name
    series_info_df[i, 2] <-
      graph_series$graphs[[i]]$graph_info$graph_name

    # Add the graph time
    series_info_df[i, 3] <-
      as.POSIXct(
        graph_series$graphs[[i]]$graph_info$graph_time,
        tz = graph_series$graphs[[i]]$graph_info$graph_tz,
        origin = "1970-01-01")

    # Add the graph time zone
    series_info_df[i, 4] <-
      graph_series$graphs[[i]]$graph_info$graph_tz

    # Add the count of nodes in the graph
    series_info_df[i, 5] <-
      nrow(graph_series$graphs[[i]]$nodes_df)

    # Add the count of nodes in the graph
    series_info_df[i, 6] <-
      nrow(graph_series$graphs[[i]]$edges_df)

    # Add TRUE/FALSE value on whether graph is directed
    series_info_df[i, 7] <-
      is_graph_directed(graph_series$graphs[[i]])
  }

  series_info_df
}