# v_kmeanlbg

## PURPOSE

V_KMEANLBG Vector quantisation using the Linde-Buzo-Gray algorithm [X,ESQ,J]=(D,K)

## SYNOPSIS

function [x,esq,j] = v_kmeanlbg(d,k)

## DESCRIPTION

    V_KMEANLBG Vector quantisation using the Linde-Buzo-Gray algorithm [X,ESQ,J]=(D,K)

    Inputs:
     D contains data vectors (one per row)
     K is number of centres required

    Outputs:
     X is output row vectors (K rows)
     ESQ is mean square error
     J indicates which centre each data vector belongs to

      Implements LBG K-means algorithm:
     Linde, Y., A. Buzo, and R. M. Gray,
     "An Algorithm for vector quantiser design,"
     IEEE Trans Communications, vol. 28, pp.84-95, Jan 1980.

## CROSS-REFERENCE INFORMATION

This function calls:

- v_kmeans V_KMEANS Vector quantisation using K-means algorithm [X,ESQ,J]=(D,K,X0,L)

This function is called by:

## SOURCE CODE

    0001 function [x,esq,j] = v_kmeanlbg(d,k)
    0002 %V_KMEANLBG Vector quantisation using the Linde-Buzo-Gray algorithm [X,ESQ,J]=(D,K)
    0003 %
    0004 %Inputs:
    0005 % D contains data vectors (one per row)
    0006 % K is number of centres required
    0007 %
    0008 %Outputs:
    0009 % X is output row vectors (K rows)
    0010 % ESQ is mean square error
    0011 % J indicates which centre each data vector belongs to
    0012 %
    0013 %  Implements LBG K-means algorithm:
    0014 % Linde, Y., A. Buzo, and R. M. Gray,
    0015 % "An Algorithm for vector quantiser design,"
    0016 % IEEE Trans Communications, vol. 28, pp.84-95, Jan 1980.
    0017
    0018
    0019 %      Copyright (C) Mike Brookes 1998
    0020 %      Version: $Id: v_kmeanlbg.m 10865 2018-09-21 17:22:45Z dmb $
    0021 %
    0022 %   VOICEBOX is a MATLAB toolbox for speech processing.
    0023 %   Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html
    0024 %
    0025 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    0026 %   This program is free software; you can redistribute it and/or modify
    0027 %   it under the terms of the GNU Lesser General Public License as published by
    0028 %   the Free Software Foundation; either version 3 of the License, or
    0029 %   (at your option) any later version.
    0030 %
    0031 %   This program is distributed in the hope that it will be useful,
    0032 %   but WITHOUT ANY WARRANTY; without even the implied warranty of
    0033 %   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    0034 %   GNU Lesser General Public License for more details.
    0035 %
    0036 %   You can obtain a copy of the GNU Lesser General Public License from
    0037 %   https://www.gnu.org/licenses/ .
    0038 %
    0039 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    0040
    0041 nc=size(d,2);
    0042 [x,esq,j]=v_kmeans(d,1);
    0043 m=1;
    0044 while m<k
    0045    n=min(m,k-m);
    0046    m=m+n;
    0047    e=1e-4*sqrt(esq)*rand(1,nc);
    0048    [x,esq,j]=v_kmeans(d,m,[x(1:n,:)+e(ones(n,1),:); x(1:n,:)-e(ones(n,1),:); x(n+1:m-n,:)]);
    0049 end