Unformatted text preview: ume that is between r=1ε
and r=1. Why do you expect this to work better? Vd ( r ) = k d · r d The required fraction is: Vd (1)
Related fact: Vd (1
Vd (1) ✏) =1 (1 ✏)d The ratio of the volume of the unit sphere and unit cube tends
to 0 as d goes to inifnity.
23 6 10/21/13 kNN kNN Use the closest k neighbors to make a decision instead of a
single nearest neighbor Use the closest k neighbors to make a decision instead of a
single nearest neighbor Choose the label that occurs among the majority of the k
nearest neighbors Choose the label that occurs among the majority of the k
nearest neighbors Can produce confidence scores. How? Other refinements: an example’s vote is inversely proportional
to its distance NN vs kNN Nearest neighbor regression
How do turn kNN into a regression method? The data Using
1 NN Using
5 NN
white regions occur
where there ties
Images from http://en.wikipedia.org/wiki/Knearest_neighbors_algorithm 28 7 10/21/13 Distances and kernels Distances and kernels The Euclidean dista...
View
Full Document
 Fall '08
 Anderson,C
 Machine Learning, Distance, Nearest neighbor search, University of Bristol, nearest neighbor, Peter Flach

Click to edit the document details