update reward fn

Author: Tong Li

applications/ColossalChat/coati/distributed/reward/reward_fn.py

@@ -11,7 +11,7 @@ def math_reward_fn(input_ids, gt_answer, response_idx, **kwargs):
         return reward
 
     decoded_final_answer = tokenizer.decode(input_ids[s : e + 1], skip_special_tokens=True)
-    gt_answer = tokenizer.decode(gt_answer.squeeze(0))
+    gt_answer = tokenizer.decode(gt_answer.squeeze(0), skip_special_tokens=True)
     final_answer, processed_str = extract_solution(decoded_final_answer)
 
     format_valid = validate_response_structure(processed_str, kwargs["tags"])
@@ -20,7 +20,7 @@ def math_reward_fn(input_ids, gt_answer, response_idx, **kwargs):
     else:
         reward += 1.0
         if gt_answer.strip().replace(" ", "").lower() == final_answer.strip().replace(" ", "").lower():
-            reward = reward + 9.0
+            reward = reward + 2.0
         return reward