euclidean distance is usually not good for sparse data are classical distances usually not good why is euclidean distance not useful why are classical distances weakly discriminant which is an example of a classical distance? what is the difference between classical and euclidean distance? is a euclidean distance usually insufficient for sparse data why is the classical distance weakly discriminant? why is classical distance weak discriminant why are classical distances often not useful why is euclidean distance weak why euclidean distance is usually not good which euclidean distance is usually not good for sparse data? is euclidean distance good is euclidean distance always not useful why is euclidean distance not good for sparse data euclidean distance is typically not good for sparse data in statistics is classical distance discriminant which type of distance is usually not good for sparse data? whose distance is euclidean