updating kmeans based on Tianqi feedback. More efficient now

src/utils.h

@@ -161,16 +161,6 @@ inline void Error(const char *fmt, ...) {
 }
 #endif
 
-/*!\brief computes the dot product between two dense vectors */
-inline float DotProduct(const std::vector<float>& v1, const std::vector<float>& v2) {
-  utils::Assert(v1.size() == v2.size(), "Arrays have different sizes");
-  float result = 0.0f;
-  for (int i = 0; i < v1.size(); ++i) {
-    result += v1[i] * v2[i];
-  }
-  return result;
-}
-
 /*! \brief replace fopen, report error when the file open fails */
 inline std::FILE *FopenCheck(const char *fname, const char *flag) {
   std::FILE *fp = fopen64(fname, flag);