From 95b9208b131dfc0810f73d512b6f15bebbe2152c Mon Sep 17 00:00:00 2001
From: Stephen Hu <stephenhu@seismic.com>
Date: Tue, 22 Jul 2025 10:04:00 +0800
Subject: [PATCH] Fix:Improve float operation when rerank (#8963)

### What problem does this PR solve?

https://github.com/infiniflow/ragflow/issues/8915

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
---
 rag/llm/rerank_model.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rag/llm/rerank_model.py b/rag/llm/rerank_model.py
index a638375f6..de6efb87b 100644
--- a/rag/llm/rerank_model.py
+++ b/rag/llm/rerank_model.py
@@ -358,7 +358,7 @@ class OpenAI_APIRerank(Base):
         max_rank = np.max(rank)
 
         # Avoid division by zero if all ranks are identical
-        if max_rank - min_rank != 0:
+        if np.isclose(min_rank, max_rank, atol=1e-3):
             rank = (rank - min_rank) / (max_rank - min_rank)
         else:
             rank = np.zeros_like(rank)