From b312d95896ab35a1b1f2b6c3d3d3ae5d436e18eb Mon Sep 17 00:00:00 2001
From: Reed Johns <115313701+vertumnal@users.noreply.github.com>
Date: Mon, 8 Dec 2025 18:22:38 -0700
Subject: [PATCH 1/3] Validate edge weights in Graclus clustering

Added validation to check for negative edge weights in Graclus clustering.
---
 torch_cluster/graclus.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/torch_cluster/graclus.py b/torch_cluster/graclus.py
index 7fa834d6..5f6aeb86 100644
--- a/torch_cluster/graclus.py
+++ b/torch_cluster/graclus.py
@@ -51,6 +51,9 @@ def graclus_cluster(
     row, col = row[perm], col[perm]
 
     if weight is not None:
+        if (weight < 0).any().item():
+            raise ValueError(f"PyG's implementation of Graclus clustering "
+                            f"does not support negative edge weights.")
         weight = weight[perm]
 
     deg = row.new_zeros(num_nodes)

From d5e4fef163457f4423616acfbc705c1315209085 Mon Sep 17 00:00:00 2001
From: Reed Johns <115313701+vertumnal@users.noreply.github.com>
Date: Mon, 8 Dec 2025 18:35:09 -0700
Subject: [PATCH 2/3] Prevent negative edge weights in Graclus

Change to flake8 standards and move to first weight is not None call
---
 torch_cluster/graclus.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/torch_cluster/graclus.py b/torch_cluster/graclus.py
index 5f6aeb86..7ed75aee 100644
--- a/torch_cluster/graclus.py
+++ b/torch_cluster/graclus.py
@@ -39,6 +39,9 @@ def graclus_cluster(
     row, col = row[mask], col[mask]
 
     if weight is not None:
+        if (weight < 0).any().item():
+            raise ValueError(f"PyG's implementation of Graclus clustering "
+                             f"does not support negative edge weights.")
         weight = weight[mask]
 
     # Randomly shuffle nodes.
@@ -51,9 +54,6 @@ def graclus_cluster(
     row, col = row[perm], col[perm]
 
     if weight is not None:
-        if (weight < 0).any().item():
-            raise ValueError(f"PyG's implementation of Graclus clustering "
-                            f"does not support negative edge weights.")
         weight = weight[perm]
 
     deg = row.new_zeros(num_nodes)

From 2c104c7a995829f6b189069810f81449db1ea70f Mon Sep 17 00:00:00 2001
From: Reed Johns <115313701+vertumnal@users.noreply.github.com>
Date: Mon, 8 Dec 2025 19:23:58 -0700
Subject: [PATCH 3/3] Implement error check for negative edge weights

Fix flake8 formatting
---
 torch_cluster/graclus.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/torch_cluster/graclus.py b/torch_cluster/graclus.py
index 7ed75aee..ef73df6f 100644
--- a/torch_cluster/graclus.py
+++ b/torch_cluster/graclus.py
@@ -40,8 +40,8 @@ def graclus_cluster(
 
     if weight is not None:
         if (weight < 0).any().item():
-            raise ValueError(f"PyG's implementation of Graclus clustering "
-                             f"does not support negative edge weights.")
+            raise ValueError("PyG's implementation of Graclus clustering "
+                             "does not support negative edge weights.")
         weight = weight[mask]
 
     # Randomly shuffle nodes.