Is this true?: “If the distance between two items is high but it is in the direction of low variance then they are not so dissimilar? While on the other hand if distance between those two items is high and it is in the direction of high variance then they are actually dissimilar?”

Question

I don’t know if I understood correctly from the professor.

I am studying big data, and professor was talking about similarity between different items of the same dataset. Image he was talking about: https://ibb.co/5RKFQLX

In: 0

Answer 1

I don’t believe your statement is globally true. However, it sounds like you’re saying something about principal compliment analysis (PCA) in which clustering is often done by reducing complex (high dimensional) data sets into more simple sets by recovering the principal axes along the vector of the greatest variance in the data set.