math.stats.kmeans — xyz.zcaudate/math.stats 4.1.0

centroid clj

(centroid ps)

finds the central position of a group of points

(centroid [[3 3] [4 4] [5 5] [6 6]]) => [9/2 9/2]

cluster clj

(cluster ps centroids)

takes an array centroids and groups points based upon closest distance

(cluster [[0 0] [1 1] [2 2] [3 3] [4 4] [5 5] [6 6]] [[1 1] [4 4]]) => [[[0 0] [1 1] [2 2]] [[3 3] [4 4] [5 5] [6 6]]]

distance2 clj

(distance2 p0 pc)

sum of squared distances between two points

(distance2 [1 3 5] [2 4 6]) => 3

initial-centroids clj

(initial-centroids ps k)

finds a set of centroids from the initial set of points

k-means clj

(k-means ps k)

(k-means ps k max-steps)

clusters points together based on the number of groups specified

(set (k-means [[0.2 0.4] [0.2 0.3] [0.3 0.4] [1.2 0.4] [1.1 0.3] [2.3 0.4]] 2)) => (any #{[[0.2 0.4] [0.2 0.3] [0.3 0.4]] [[1.2 0.4] [1.1 0.3] [2.3 0.4]]} #{[[0.2 0.4] [0.2 0.3] [0.3 0.4] [1.2 0.4] [1.1 0.3]] [[2.3 0.4]]})

min-index clj

(min-index p0 centroids)

finds the index of the centroid closest to p0

(min-index [0 0] [[-1 -1] [0.5 0.5] [1 1]]) => 1