R: indices and distances of k-nearest-neighbors using a distance...

distMat.knn.index.dist {KernelKnn} | R Documentation

## indices and distances of k-nearest-neighbors using a distance matrix

### Description

indices and distances of k-nearest-neighbors using a distance matrix

### Usage

    distMat.knn.index.dist(DIST_mat, TEST_indices = NULL, k = 5, threads = 1,
      minimize = T)

### Arguments

`DIST_mat` | a distance matrix (square matrix) having a diagonal filled with either zero's (0) or NA's (missing values)
`TEST_indices` | a numeric vector specifying the indices of the test data in the distance matrix (row-wise or column-wise). If the parameter equals NULL then no test data is included in the distance matrix
`k` | an integer specifying the k-nearest-neighbors
`threads` | the number of cores to be used in parallel (openmp will be employed)
`minimize` | either TRUE or FALSE. If TRUE then lower values will be considered as relevant for the k-nearest search, otherwise higher values.

### Details

This function takes a number of arguments and it returns the indices and distances of the k-nearest-neighbors for each observation. If TEST_indices is NULL then the indices-distances for the DIST_mat be returned, whereas if TEST_indices is not NULL then the indices-distances for the test data only will be returned.

### Value

a list of length 2. The first sublist returns the indices and the second the distances of the k nearest neighbors for each observation. If TEST_indices is NULL the number of rows of each sublist equals the number of rows in the DIST_mat data. If TEST_indices is not NULL the number of rows of each sublist equals the length of the input TEST_indices.

### Author(s)

Lampros Mouselimis

### Examples

    data(Boston)

    X = Boston[, -ncol(Boston)]

    dist_obj = dist(X)

    dist_mat = as.matrix(dist_obj)

    out = distMat.knn.index.dist(dist_mat, TEST_indices = NULL, k = 5)

[Package KernelKnn version 1.0.8 Index]