R: Compute L2 distance between two vectors of numbers.

l2norm {wavethresh} | R Documentation

## Compute L2 distance between two vectors of numbers.

### Description

Compute L2 distance between two vectors of numbers (square root of sum of squares of differences between two vectors).

### Usage

    l2norm(u,v)

### Arguments

`u` | first vector of numbers
`v` | second vector of numbers

### Details

Function simply computes the L2 distance between two vectors and is implemented as

`sqrt(sum((u-v)^2))`

### Value

A real number which is the L2 distance between two vectors.

### RELEASE

Version 3.6 Copyright Guy Nason 1995

### Note

This function would probably be more accurate if it used the Splus function `vecnorm`.

### Author(s)

G P Nason

### See Also

`linfnorm`, `wstCV`, `wstCVl`.

### Examples

    #
    # What is the L2 norm between the following sets of vectors
    #
    p <- c(1,2,3,4,5)
    q <- c(1,2,3,4,5)
    r <- c(2,3,4,5,6)
    l2norm(p,q)
    # [1] 0
    l2norm(q,r)
    # [1] 2.236068
    l2norm(r,p)
    # [1] 2.236068

[Package wavethresh version 4.6.8 Index]