isodata.m

这是一个有关于模式识别中的isodata算法的matlab源码。 大家可以看看。有详细注释

function [Z, Xcluster, Ycluster, A, cluster] = isodata(X, Y, k, L, I, ON, OC, OS, NO, min);
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Parametros interos de la funcion  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
s=size(X);
s=s(2);
cluster=zeros(1,s); % Espacio temporal interno de la funcion.
iter=0;
final=0;
vuelve3=0;
A=1;     % Lo inicializamos para el primer caso.
primeravez=1;   % Para en el primer cilo del while no nos pida la modificacion de parametros.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  1.Inicializacion de los centros  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Z= inicializa_centros(X, Y, A);


%%%%%%%%%%%%%%%%%%%%%%%%
%  Programa principal  %
%%%%%%%%%%%%%%%%%%%%%%%%

while final==0,   %inicio del bucle de iteraciones.
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%  2.Establecer los valores de los parametros  %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
    if primeravez==0,
		if vuelve3==0,
            [Ltemp, Itemp, ktemp, ONtemp, OCtemp, OStemp]=parametros(L, I, k, ON, OC, OS, iter);
        end;
    end;
	
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%  3.Calcula y asigna a cada coordenada {X,Y} su centro mas cercano  %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    primeravez=0;
	vuelve3=1;
	for i=1:s,
        cluster(i)=cercano(X(i), Y(i), Z, A);
	end;
	
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%  4.Eliminar agrupamientos  %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% Funcion que nos reduce (si hace falta) el numero de centros y de agrupamientos encontrados.
	[Z, A, cluster]=eliminar(A, cluster, Z, X, Y, ON);
    
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%  5.Actualiza los centros de los agrupamientos  %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	Z=recalcula(cluster, X, Y, A, Z);
    
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%  6.Terminar, dividir o mezclar  %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    if (iter==I),
        final=1;
        next=0;
	else
        next=decide78(iter, k, A);
    end;


	%%%%%%%%%%%%%%%
	%  7.Dividir  %
	%%%%%%%%%%%%%%%
	if next==1,
        next=2;
        hubo_division=0;
        A2=A;
  	    divide=0;
        % Dispersion por agrupamiento, dispersion global
        % Y dispersion por variable y componente de maxima dispersion por orden respectivo.
        [Di, D, STM]= dispersion(X, Y, Z, cluster, A);
	
        % Division / Divide todos los agrupamientos que cumplan la condicion
		i=0;    % Si se cumplen las condiciones realiza una division e itera.                           
		while (hubo_division==0) & (i < A),      % Si para algun...                                     
		    i=i+1;                                                                                      
		    index=find(cluster==i); % Index nos indica los valores del agrupamiento a particionar.      
		    sindex=size(index);                                                                         
		    sindex=sindex(2);                                                                           
		    if  (STM(i)>OS) & (  ((Di(i,1)>D(1)) & (Di(i,2)>D(2)) & (sindex>(2*(ON+1)))) | (A<=(k/2)) ), 
		        hubo_division=1;                                                                        
		        next=1;                                                                                 
		        [Z, cluster]=dividir(STM, A, cluster, Z, i, (A+1), X, Y);    % Division.                 
		        A=A+1;  % Indicamos que hay un nuevo agrupamiento.                                      
		        iter=iter+1;                                                                            
		   end;                                                                                         
		end;                                                                                            

    end;

    
	%%%%%%%%%%%%%%%
	%  8.Mezclar  %
	%%%%%%%%%%%%%%%
	if  next==2,
        %Calcula y ordena las L distancias menores entre los centros.
        [orden, Dij]= distancia_centros(A, Z, OC, L);   %Si orden==0 --> no hay nada para mezclar.
        % Union de agrupamientos.
        if  orden(1) > 0,
            [cluster, Z, A]=union(A, orden, cluster, Z, Dij);
            % Recacula los centros.
            Z=recalcula(cluster, X, Y, A, Z);
        end;
	end;
	
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%  9.Terminar o volver a iterar  %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	if next==2
        [iter,final,vuelve3]= termina_o_itera(iter, I, NO);
    end;
    
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Final del while(bucle principal del programa)  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
end;    
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Elmina puntos que no cumplan al minima distancia  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for j=1:s
    temp=0;
    P=[X(j) Y(j)];
    for i=1:A,
        if distancia(P,Z(i,:)) > min,
            temp=temp+1;
        end;
    end;
    if  temp==A,
        cluster(j)=0;
    end;
end;



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Separamos los puntos en k vectores representativos de los k patrones  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Xcluster=0;
Ycluster=0;
for m=1:k
    inedx=0;
    index=find(cluster==m);
    s2=size(index);
    s2=s2(2);
    for n=1:s2
        Xcluster(1,n,m)= X(index(n));
        Ycluster(1,n,m)= Y(index(n));
    end;
end;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                     Fin del programa principal                        %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%





%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %              Codigo de las subfunciones utilizadas                 %%  
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Funcion para calcular el centro mas cercano a cada punto  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [m] = cercano(x, y, Z, k)
    dtemp=0;
    d=0;
    for j=1:k
        P=[x y];
        d=distancia(Z(j,:), P); % Distancia del centro al punto.
        if j<2,
            m=j;    % La primera distancia siempre es valida.
            dtemp=d;
        elseif d < dtemp,
            m=j;    % Nos quedamos con el centro al que corresponde 
            dtemp=d;  % la menor de las distancias.
        end;
    end;    
    

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Funcion para reasignar los centros  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [Zout1] = recalcula(cluster, X, Y, k, Z) %Realiza la media de los puntos asigandos a cada clase corersp. a los centros
	s=size(X);
	s=s(2);
	valor=zeros(1,k);
	Zout=zeros(k,2);
	for m=1:k
        index=find(cluster==m);
        if isempty(index)==0
            sindex=size(index);
            sindex=sindex(2);  
            Zout1(m,1)=(sum(X(index))) / sindex;
            Zout1(m,2)=(sum(Y(index))) / sindex;        
        else
            Zout1(m,:)=Z(m,:);
        end;
	end;
    

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Dispersion por agrupamietno y dispersion global  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [Ditemp, Dtemp, STMAX] = dispersion(X, Y, Z, cluster, A)
    Ditemp=zeros(A,2);
    Dtemp=zeros(1,2);
    ST=zeros(A,2);
    STMAX=zeros(1,A);
    for i=1:A,
        suma=[0 0];
        index=find(cluster==i);
        sindex=size(index);
        for j=index,
            P=[X(j), Y(j)];
            d=distancia(Z(i,:), P  );% Distancia de Xi al centro Zi.
            suma(1)=suma(1) + (d * X(j));   % sumax
            suma(2)=suma(2) + (d * Y(j));   % sumay
        end;
        % Dispersion por agrupamiento
        Ditemp(i,:)=suma / sindex(2);
        % Dispersion global temporal
        Dtemp(1,:)=Dtemp(1,:) + (Ditemp(i,:) * sindex(2));% Sumatorio Ni*Di
        %Dispersion por variable
        ST(i,1)=std(X(index));
        ST(i,2)=std(Y(index));
        % Componente de maxima dispersion
        STMAX(i)=max(ST(i,:));
    end;
    % Dispersion global acabada
    Dtemp(1,:)=Dtemp(1,:) / A;


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Reduce el numero de centros y de agrupamientos encontrados  %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [Ztemp, Atemp, clustertemp]=eliminar(A, cluster, Z, X, Y, ON)
	%Asignacion.
    %desplazamiento: sirve para indicar que centros y agrupaviones hay que
    %eliminar
	desplazamiento=zeros(1,A);  % Sus posibles valores son: -1, (=0) o (>0).
	for i=1:A,                  % Si -1: este grupo se alimina. Si 0: no varia.