# rdist: rdist: an R package for distances In rdist: Calculate Pairwise Distances

## Description

`rdist` provide a common framework to calculate distances. There are three main functions:

• `rdist` computes the pairwise distances between observations in one matrix and returns a `dist` object,

• `pdist` computes the pairwise distances between observations in one matrix and returns a `matrix`, and

• `cdist` computes the distances between observations in two matrices and returns a `matrix`.

In particular the `cdist` function is often missing in other distance functions. All calculations involving `NA` values will consistently return `NA`.

## Usage

 ```1 2 3 4 5``` ```rdist(X, metric = "euclidean", p = 2L) pdist(X, metric = "euclidean", p = 2) cdist(X, Y, metric = "euclidean", p = 2) ```

## Arguments

 `X, Y` A matrix `metric` The distance metric to use `p` The power of the Minkowski distance

## Details

Available distance measures are (written for two vectors v and w):

• `"euclidean"`: sqrt(sum_i((v_i - w_i)^2))

• `"minkowski"`: (sum_i(|v_i - w_i|^p))^{1/p}

• `"manhattan"`: sum_i(|v_i-w_i|)

• `"maximum"` or `"chebyshev"`: max_i(|v_i-w_i|)

• `"canberra"`: sum_i(|v_i-w_i|/(|v_i|+|w_i|))

• `"angular"`: arccos(cor(v, w))

• `"correlation"`: sqrt((1-cor(v, w))/2)

• `"absolute_correlation"`: sqrt((1-|cor(v, w)|^2))

• `"hamming"`: sum_i(v_i != w_i)/sum_i(1)

• `"jaccard"`: sum_i(v_i != w_i)/sum_i(v_i != 0 or w_i != 0)

• Any function that defines a distance between two vectors.

rdist documentation built on May 4, 2020, 5:13 p.m.