Question

I got n points which belong to a rainbow (or are close to being a “rainbow color”). Now given a point which is also a rainbow color, I want to find the closest match out of the n points.

What is a robust and simple data structure + algorithm combination to do this? Using (R,G,B) tuples and Eularian distances came to my mind.

Yes, I got a serious use case 🙂

Answer 1

I’m not playing around with rainbows 😉 but I have almost the same situation and I use a kd-tree for this to quickly search the closest “point”. My points are also rgb colors in the form of 0-1 floats

http://code.google.com/p/python-kdtree/

from kdtree import KDTree

data = [(1,2,3),(4,0,1),(5,3,1),(10,5,4),(9,8,9),(4,2,4)]

tree = KDTree.construct_from_data(data)
nearest = tree.query(query_point=(5,4,3), t=1)