Neighbour: K nearest neighbours

Description Usage Arguments Value Author(s) Examples

View source: R/Neighbour.R

Description

K nearest neighbours

Usage

1
Neighbour(query, ref, k, build = "kdtree", cores = 0, checks = 1)

Arguments

query

Matrix or data frame containing the set of query points where each row represents a point.

ref

Matrix or data frame containing the set of reference points where each row represents a point.

k

Number of nearest neighbours to search for.

build

String indicating the search structure to be used: "kdtree", "kmeans", "linear"

.

cores

Number of cpu cores to be used for searching. If 0, then the maximum allowable cores are used.

checks

Number of checks during searching. Higher value gives better search precision but takes longer. See FLANN C++ manual for more details.

Value

List containing:

indices

Matrix containing the index of the nearest neighbours in the reference set for each query set of points

distances

Matrix containing the distances to the nearest neighbours

Author(s)

Yee, Jeremy

Examples

1
2
3
4
## Find the nearest neighbour using a KD Tree
query <- matrix(rnorm(10), ncol = 2)
reference <- matrix(rnorm(10), ncol = 2)
Neighbour(query, reference, 3, "kdtree", 0, 1)

Example output

$indices
     [,1] [,2] [,3]
[1,]    3    5    1
[2,]    3    5    4
[3,]    2    3    1
[4,]    5    3    1
[5,]    2    3    4

$distances
          [,1]      [,2]     [,3]
[1,] 0.3048164 0.3959277 1.247120
[2,] 0.5941663 0.8706599 2.589433
[3,] 1.5930031 2.1528606 2.929196
[4,] 1.8134292 3.0668465 4.304286
[5,] 0.1361710 1.9594569 2.685418

rflann documentation built on May 29, 2017, 12:37 p.m.