From ba2d28e3e922a0fee8356305742553db558e422a Mon Sep 17 00:00:00 2001
From: Nicholas Landry <nicholas.landry.91@gmail.com>
Date: Thu, 17 Aug 2023 13:36:33 -0400
Subject: [PATCH 1/2] Added `s` parameter to `neighbors`

---
 xgi/core/views.py | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/xgi/core/views.py b/xgi/core/views.py
index 8bea38474..ca9c9c812 100644
--- a/xgi/core/views.py
+++ b/xgi/core/views.py
@@ -330,7 +330,7 @@ def filterby_attr(self, attr, val, mode="eq", missing=None):
             )
         return type(self).from_view(self, bunch)
 
-    def neighbors(self, id):
+    def neighbors(self, id, s=1):
         """Find the neighbors of an ID.
 
         The neighbors of an ID are those IDs that share at least one bipartite ID.
@@ -339,6 +339,9 @@ def neighbors(self, id):
         ----------
         id : hashable
             ID to find neighbors of.
+        s : int, optional
+            The intersection size s to be considered neighbors.
+            By default, 1.
         Returns
         -------
         set
@@ -359,9 +362,17 @@ def neighbors(self, id):
         {1, 3, 4}
 
         """
-        return {i for n in self._id_dict[id] for i in self._bi_id_dict[n]}.difference(
-            {id}
-        )
+        if s == 1:
+            return {
+                i for n in self._id_dict[id] for i in self._bi_id_dict[n]
+            }.difference({id})
+        else:
+            return {
+                i
+                for n in self._id_dict[id]
+                for i in self._bi_id_dict[n]
+                if len(self._id_dict[id].intersection(self._id_dict[i])) >= s
+            }.difference({id})
 
     def duplicates(self):
         """Find IDs that have a duplicate.

From ac0dccfccf866bfbf729d06e325fb2ef4eaa4983 Mon Sep 17 00:00:00 2001
From: Nicholas Landry <nicholas.landry.91@gmail.com>
Date: Thu, 21 Sep 2023 15:07:54 -0400
Subject: [PATCH 2/2] Added unit tests

---
 tests/core/test_views.py | 13 ++++++++-----
 xgi/core/views.py        |  3 ++-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/tests/core/test_views.py b/tests/core/test_views.py
index ba341d794..71883d72a 100644
--- a/tests/core/test_views.py
+++ b/tests/core/test_views.py
@@ -5,11 +5,10 @@
 from xgi.exception import IDNotFound, XGIError
 
 
-def test_neighbors(edgelist1, edgelist2):
-    el1 = edgelist1
-    el2 = edgelist2
-    H1 = xgi.Hypergraph(el1)
-    H2 = xgi.Hypergraph(el2)
+def test_neighbors(edgelist1, edgelist2, edgelist7):
+    H1 = xgi.Hypergraph(edgelist1)
+    H2 = xgi.Hypergraph(edgelist2)
+    H3 = xgi.Hypergraph(edgelist7)
     assert H1.nodes.neighbors(1) == {2, 3}
     assert H1.nodes.neighbors(4) == set()
     assert H1.nodes.neighbors(6) == {5, 7, 8}
@@ -20,6 +19,10 @@ def test_neighbors(edgelist1, edgelist2):
     assert H1.edges.neighbors(1) == set()
     assert H1.edges.neighbors(2) == {3}
     assert H1.edges.neighbors(3) == {2}
+    assert H3.edges.neighbors(0, s=2) == {1}
+    assert H3.edges.neighbors(1, s=2) == {0, 2}
+    assert H3.edges.neighbors(2, s=2) == {1}
+    assert H3.edges.neighbors(3, s=2) == set()
 
 
 def test_edge_order(edgelist3):
diff --git a/xgi/core/views.py b/xgi/core/views.py
index ca9c9c812..1d4acad8a 100644
--- a/xgi/core/views.py
+++ b/xgi/core/views.py
@@ -340,8 +340,9 @@ def neighbors(self, id, s=1):
         id : hashable
             ID to find neighbors of.
         s : int, optional
-            The intersection size s to be considered neighbors.
+            The intersection size s for two edges or nodes to be considered neighbors.
             By default, 1.
+
         Returns
         -------
         set