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// Copyright ©2019 The Gonum Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vptree_test
import (
"fmt"
"log"
"gonum.org/v1/gonum/spatial/vptree"
)
func ExampleTree() {
// Example data from https://en.wikipedia.org/wiki/K-d_tree
points := []vptree.Comparable{
vptree.Point{2, 3},
vptree.Point{5, 4},
vptree.Point{9, 6},
vptree.Point{4, 7},
vptree.Point{8, 1},
vptree.Point{7, 2},
}
t, err := vptree.New(points, 3, nil)
if err != nil {
log.Fatal(err)
}
q := vptree.Point{8, 7}
p, d := t.Nearest(q)
fmt.Printf("%v is closest point to %v, d=%f\n", p, q, d)
// Output:
// [9 6] is closest point to [8 7], d=1.414214
}
func ExampleTree_Do() {
// Example data from https://en.wikipedia.org/wiki/K-d_tree
points := []vptree.Comparable{
vptree.Point{2, 3},
vptree.Point{5, 4},
vptree.Point{9, 6},
vptree.Point{4, 7},
vptree.Point{8, 1},
vptree.Point{7, 2},
}
// Print all points in the data set within 3 of (3, 5).
t, err := vptree.New(points, 0, nil)
if err != nil {
log.Fatal(err)
}
q := vptree.Point{3, 5}
t.Do(func(c vptree.Comparable, _ int) (done bool) {
// Compare each distance and output points
// with a Euclidean distance less than or
// equal to 3. Distance returns the
// Euclidean distance between points.
if q.Distance(c) <= 3 {
fmt.Println(c)
}
return
})
// Unordered output:
// [2 3]
// [4 7]
// [5 4]
}
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