wolffd@0: function [V,I]=som_divide(sMap, D, inds, mode)
wolffd@0: 
wolffd@0: %SOM_DIVIDE Divides a dataset according to a given map.
wolffd@0: %
wolffd@0: % [V,I]=som_divide(sMap, sData, [inds], [mode])
wolffd@0: %
wolffd@0: % ARGUMENTS ([]'s are optional) 
wolffd@0: %
wolffd@0: %  sMap     (struct or matrix) map struct or codebook (size munits x dim)
wolffd@0: %  sData    (struct or matrix) data struct or matrix (size N x dim )
wolffd@0: %  [inds]            From which map units should the local data sets
wolffd@0: %                    be constructed. Interpretation depends on mode
wolffd@0: %                    argument. By default [1:munits].
wolffd@0: %           'class': (vector) munits x 1 matrix of class numbers
wolffd@0: %           'index': (vector) K x 1 vector of map node indexes 
wolffd@0: %           'index': (matrix) K x k matrix of map node subscripts
wolffd@0: %  [mode]   (string) 'index' or 'class', if inds is a vector of length 
wolffd@0: %                    munits, default is 'class', otherwise 'index'.
wolffd@0: % RETURNS
wolffd@0: %  
wolffd@0: % If mode == 'index' 
wolffd@0: %  V        (matrix) data vectors hitting the specified nodes (size K x dim)                   
wolffd@0: %  I        (vector) corresponding data row indexes (size K x 1)
wolffd@0: %   
wolffd@0: % If mode == 'class' (this can be used after using som_select)
wolffd@0: %  V        (cell array) V{K} includes vectors whose BMU has class number 
wolffd@0: %                        K in the input matrix 'coord'. Note that 
wolffd@0: %                        values of K below 1 are ignored. 
wolffd@0: %  I        (cell array) corresponding data indexes in the cell array                        
wolffd@0: %
wolffd@0: % NOTE: if the same node is specified multiple times, only one
wolffd@0: %       set of hits is returned.
wolffd@0: %
wolffd@0: % See also SOM_BMU, SOM_HITS, SOM_SELECT.
wolffd@0: 
wolffd@0: % Version 1.0beta 260997 Johan 
wolffd@0: % Version 2.0beta 230300 juuso
wolffd@0: 
wolffd@0: % Contributed to SOM Toolbox vs2, Mar 23rd, 2000 by Juha Vesanto
wolffd@0: % http://www.cis.hut.fi/projects/somtoolbox/
wolffd@0: 
wolffd@0: %%%% Init & Check %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
wolffd@0: 
wolffd@0: error(nargchk(0, 4, nargin)) % check if no. of input args is correct
wolffd@0: 
wolffd@0: % map
wolffd@0: if isstruct(sMap), 
wolffd@0:   msize = sMap.topol.msize;     
wolffd@0:   dim = size(sMap.codebook,2); 
wolffd@0: else
wolffd@0:   msize = [size(sMap,1) 1];
wolffd@0:   dim = size(sMap,2); 
wolffd@0: end
wolffd@0: munits = prod(msize);
wolffd@0: 
wolffd@0: % data
wolffd@0: if isstruct(D), D=D.data; end
wolffd@0: 
wolffd@0: % inds
wolffd@0: if nargin<3, inds = 1:munits; end
wolffd@0: isvec = prod(size(inds))==length(inds);
wolffd@0: 
wolffd@0: % mode
wolffd@0: if nargin<4, 
wolffd@0:   if isvec & length(inds)==munits, 
wolffd@0:     mode = 'class'; 
wolffd@0:   else
wolffd@0:     mode = 'index'; 
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: %%% Action & Build output according to the mode string output
wolffd@0: 
wolffd@0: if ~isvec, inds = som_sub2ind(msize,inds); end
wolffd@0: 
wolffd@0: bmus=som_bmus(sMap,D); 
wolffd@0: 
wolffd@0: switch mode
wolffd@0:  case 'index'
wolffd@0:   I=find(ismember(bmus,inds));         
wolffd@0:   V=D(I,:);
wolffd@0:  case 'class'   
wolffd@0:   K=max(inds); % classes  
wolffd@0:   V = cell(K,1); 
wolffd@0:   I = cell(K,1);
wolffd@0:   for i=1:K,
wolffd@0:     N_ind=find(inds == i);           % indexes of the units of class i
wolffd@0:     I{i}=find(ismember(bmus,N_ind)); % data indexes       
wolffd@0:     V{i}=D(I{i},:);
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: 
wolffd@0: 
wolffd@0: 
wolffd@0: