vptree

type Metric ¶

type Metric func(a, b interface{}) float64

A Metric is a function that measures the distance between two provided interface{}-values. The function *must* be a metric in the mathematical sense, that is, the metric d must fullfill the following requirements:

• d(x, y) >= 0
• d(x, y) = 0 if and only if x = y
• d(x, y) = d(y, x)
• d(x, z) <= d(x, y) + d(y, z) (triangle inequality)

type TreeItem ¶

type TreeItem interface {
	Distance(TreeItem) float64
}

type VPTree ¶

type VPTree struct {
	Root   *node
	Length int
}

A VPTree struct represents a Vantage-point tree. Vantage-point trees are useful for nearest-neighbour searches in high-dimensional metric spaces.

func New(items []TreeItem) (t *VPTree)

func (vp *VPTree) Search(target TreeItem, k int) (results []TreeItem, distances []float64)