From 935cdad84003d211c34ab1a6efeeeae6724a51f7 Mon Sep 17 00:00:00 2001
From: robinlovelace <rob00x@gmail.com>
Date: Fri, 2 Aug 2024 14:17:57 +0100
Subject: [PATCH] Only run rnet_group() examples when igraph installed

Close #565
---
 R/rnet_group.R    | 5 +++++
 man/rnet_group.Rd | 6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/R/rnet_group.R b/R/rnet_group.R
index 68e46052..d1fbf414 100644
--- a/R/rnet_group.R
+++ b/R/rnet_group.R
@@ -21,9 +21,13 @@
 #'   rnet_group representing the groups of each network element. In the latter
 #'   case, the connectivity of the spatial object is derived from the sfNetwork
 #'   object.
+#' 
+#' @note These functions rely on the igraph package. If igraph is not installed,
+#'   the function will return a message.
 #'
 #' @family rnet
 #' @examples
+#' if (requireNamespace("igraph", quietly = TRUE)) {
 #' rnet <- rnet_breakup_vertices(stplanr::osm_net_example)
 #' rnet$group <- rnet_group(rnet)
 #' plot(rnet["group"])
@@ -36,6 +40,7 @@
 #' plot(rnet["group_louvain"])
 #' rnet$group_fast_greedy <- rnet_group(rnet, igraph::cluster_fast_greedy)
 #' plot(rnet["group_fast_greedy"])
+#' }
 #' @export
 rnet_group <- function(rnet, ...) {
   UseMethod("rnet_group")
diff --git a/man/rnet_group.Rd b/man/rnet_group.Rd
index b0ccc051..edca5a24 100644
--- a/man/rnet_group.Rd
+++ b/man/rnet_group.Rd
@@ -65,7 +65,12 @@ functions are available:
 \verb{cluster_edge_betweenness, cluster_fast_greedy, cluster_label_prop,}
 \verb{cluster_leading_eigen, cluster_louvain, cluster_optimal, cluster_spinglass, cluster_walktrap}
 }
+\note{
+These functions rely on the igraph package. If igraph is not installed,
+the function will return a message.
+}
 \examples{
+if (requireNamespace("igraph", quietly = TRUE)) {
 rnet <- rnet_breakup_vertices(stplanr::osm_net_example)
 rnet$group <- rnet_group(rnet)
 plot(rnet["group"])
@@ -79,6 +84,7 @@ plot(rnet["group_louvain"])
 rnet$group_fast_greedy <- rnet_group(rnet, igraph::cluster_fast_greedy)
 plot(rnet["group_fast_greedy"])
 }
+}
 \seealso{
 Other rnet: 
 \code{\link{gsection}()},