# kmeans: Question about feature values

In an example about kmeans for exploratory analysis the instructor examines the centroids and affirms that the centroid coordinates with the highest values are those that "drive" “belonging” to that cluster.

I am unable to understand that.

As an example let’s take a centroid that has, among its N coordinates, coordinates with values 100, 90, -90, -100. I am unable to understand why the coordinates with value 100 and 90 should “drive” the “belonging" to that cluster more than coordinates with value -90 or -100. Euclidean distance seems a relative measure to me, so absolute values should not matter, in general. It seems to me that what the instructor says might be true only if we assume non-negative domains for all the coordinates (not the case in the example he makes).

Can someone help me to understand, correct, confirm, integrate?

• it would help if you provided an accurate description of what the instructor said (or just talk ot him/her :) ). possibly they were talking about the squaring of euclidean distance, meaning that belonging will depend on the component with the largest difference ( 1 component wih absolute difference 10 beats 10 components with absolute difference 1) Jan 14, 2018 at 13:43
• Unfortunately the description is accurate, he said that, no more than that, (that is a systematic problem with that course) and, as I wrote, he was speaking about values of coordinates, not about distances
– user110848
Jan 14, 2018 at 14:53