feat: voronoi()

igraph · Feb 1, 2024 · d40b2e7 · d40b2e7
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Showing 25 changed files with 170 additions and 21 deletions.
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -70,5 +70,5 @@ Config/testthat/start-first: vs-es, scan, vs-operators, weakref,
     watts.strogatz.game
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.3.0.9000
+RoxygenNote: 7.3.1
 SystemRequirements: gmp, libxml2, glpk (>= 4.57)
diff --git a/NAMESPACE b/NAMESPACE
@@ -861,6 +861,7 @@ export(vertex_attr_names)
 export(vertex_connectivity)
 export(vertex_disjoint_paths)
 export(vertices)
+export(voronoi)
 export(walktrap.community)
 export(watts.strogatz.game)
 export(weighted_clique_num)

diff --git a/R/aaa-auto.R b/R/aaa-auto.R
@@ -740,8 +740,9 @@ distances_floyd_warshall_impl <- function(graph, from=V(graph), to=V(graph), wei
   res
 }
 
-voronoi_impl <- function(graph, generators, weights=NULL, mode=c("out", "in", "all", "total"), tiebreaker=c("random", "first", "last")) {
+voronoi_impl <- function(graph, generators, ..., weights=NULL, mode=c("out", "in", "all", "total"), tiebreaker=c("random", "first", "last")) {
   # Argument checks
+  check_dots_empty()
   ensure_igraph(graph)
   generators <- as_igraph_vs(graph, generators)
   if (is.null(weights) && "weight" %in% edge_attr_names(graph)) {

diff --git a/R/community.R b/R/community.R
@@ -2782,3 +2782,44 @@ communities <- groups.communities
 #' @export
 #' @family functions for manipulating graph structure
 contract <- contract_vertices_impl
+
+
+#' Voronoi partitioning of a graph
+#'
+#' @description
+#' `r lifecycle::badge("experimental")`
+#'
+#' This function partitions the vertices of a graph based on a set of generator
+#' vertices. Each vertex is assigned to the generator vertex from (or to) which
+#' it is closest.
+#'
+#' [groups()] may be used on the output of this function.
+#'
+#' @param graph The graph to partition into Voronoi cells.
+#' @param generators The generator vertices of the Voronoi cells.
+#' @param mode Character string. In directed graphs, whether to compute
+#'   distances from generator vertices to other vertices (`"out"`), to
+#'   generator vertices from other vertices (`"in"`), or ignore edge
+#'   directions entirely (`"all"`). Ignored in undirected graphs.
+#' @param tiebreaker Character string that specifies what to do when a vertex
+#'   is at the same distance from multiple generators. `"random"` assigns
+#'   a minimal-distance generator randomly, `"first"` takes the first one,
+#'   and `"last"` takes the last one.
+#' @inheritParams distances
+#' @inheritParams rlang::args_dots_empty
+#' @return A named list with two components:
+#'   \item{membership}{numeric vector giving the cluster id to which each vertex
+#'   belongs.}
+#'   \item{distances}{numeric vector giving the distance of each vertex from its
+#'   generator}
+#' @seealso [distances()]
+#' @examples
+#'
+#' g <- make_lattice(c(10,10))
+#' clu <- voronoi(g, c(25, 43, 67))
+#' groups(clu)
+#' plot(g, vertex.color=clu$membership)
+#'
+#' @export
+#' @family community
+voronoi <- voronoi_impl
diff --git a/man/as_membership.Rd b/man/as_membership.Rd
diff --git a/man/cluster_edge_betweenness.Rd b/man/cluster_edge_betweenness.Rd
diff --git a/man/cluster_fast_greedy.Rd b/man/cluster_fast_greedy.Rd
diff --git a/man/cluster_fluid_communities.Rd b/man/cluster_fluid_communities.Rd
diff --git a/man/cluster_infomap.Rd b/man/cluster_infomap.Rd
diff --git a/man/cluster_label_prop.Rd b/man/cluster_label_prop.Rd
diff --git a/man/cluster_leading_eigen.Rd b/man/cluster_leading_eigen.Rd
diff --git a/man/cluster_leiden.Rd b/man/cluster_leiden.Rd
diff --git a/man/cluster_louvain.Rd b/man/cluster_louvain.Rd
diff --git a/man/cluster_optimal.Rd b/man/cluster_optimal.Rd
diff --git a/man/cluster_spinglass.Rd b/man/cluster_spinglass.Rd
diff --git a/man/cluster_walktrap.Rd b/man/cluster_walktrap.Rd
diff --git a/man/communities.Rd b/man/communities.Rd
diff --git a/man/compare.Rd b/man/compare.Rd
diff --git a/man/groups.Rd b/man/groups.Rd
diff --git a/man/make_clusters.Rd b/man/make_clusters.Rd
diff --git a/man/modularity.igraph.Rd b/man/modularity.igraph.Rd
diff --git a/man/plot_dendrogram.communities.Rd b/man/plot_dendrogram.communities.Rd
diff --git a/man/split_join_distance.Rd b/man/split_join_distance.Rd
diff --git a/man/voronoi.Rd b/man/voronoi.Rd
diff --git a/tools/stimulus/functions-R.yaml b/tools/stimulus/functions-R.yaml
@@ -367,6 +367,7 @@ igraph_distances_johnson:
 igraph_distances_floyd_warshall:
 
 igraph_voronoi:
+    FIRST_KW_PARAM: weights
 
 igraph_get_all_simple_paths:
     IGNORE: RR