Merge pull request #2548 from Zheng-Bicheng/develop

Update cosine_similarity.cc

Author: Jiang-Jia-Jun

fastdeploy/vision/utils/cosine_similarity.cc

@@ -23,24 +23,19 @@ float CosineSimilarity(const std::vector<float>& a, const std::vector<float>& b,
   FDASSERT((a.size() == b.size()) && (a.size() != 0),
            "The size of a and b must be equal and >= 1.");
   size_t num_val = a.size();
+  float mul_ab = 0.f;
   if (normalized) {
-    float mul_a = 0.f, mul_b = 0.f, mul_ab = 0.f;
     for (size_t i = 0; i < num_val; ++i) {
-      mul_a += (a[i] * a[i]);
-      mul_b += (b[i] * b[i]);
       mul_ab += (a[i] * b[i]);
     }
-    return (mul_ab / (std::sqrt(mul_a) * std::sqrt(mul_b)));
+    return mul_ab;
   }
   auto norm_a = L2Normalize(a);
   auto norm_b = L2Normalize(b);
-  float mul_a = 0.f, mul_b = 0.f, mul_ab = 0.f;
   for (size_t i = 0; i < num_val; ++i) {
-    mul_a += (norm_a[i] * norm_a[i]);
-    mul_b += (norm_b[i] * norm_b[i]);
     mul_ab += (norm_a[i] * norm_b[i]);
   }
-  return (mul_ab / (std::sqrt(mul_a) * std::sqrt(mul_b)));
+  return mul_ab;
 }
 
 }  // namespace utils