From e35704d13057a395cab48b78413c61f93e9f4089 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Thu, 16 Oct 2025 23:33:31 +0200
Subject: [PATCH] rogueviz::som:: in normalize, fix weird stuff happening when
 there is no variance

---
 rogueviz/som/kohonen.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/rogueviz/som/kohonen.cpp b/rogueviz/som/kohonen.cpp
index c8fa60ca..eb25d1c7 100644
--- a/rogueviz/som/kohonen.cpp
+++ b/rogueviz/som/kohonen.cpp
@@ -39,7 +39,8 @@ void normalize() {
       sum += s.val[k],
       sqsum += s.val[k] * s.val[k];
     double variance = sqsum/samples - sqr(sum/samples);
-    weights[k] = 1 / sqrt(variance);
+    if(variance == 0) weights[k] = 1;
+    else weights[k] = 1 / sqrt(variance);
     }
   }