function [ grouped ] = grouped( indices, varargin )

    if iscell(indices)
        I = indices;
    else
        I = grouped_indices( indices );
    end
        
	if isempty(varargin)
		grouped = I;
		return
	end

    names  = varargin(1:2:end);
    values = varargin(2:2:end);        
    
    %grouped(length(I)) = struct;
    %for i=1:length(I)
    for i=length(I):-1:1
    
        elem = struct;
        
        for j=1:length(names)
            name  = names{j};
            value = submat( values{j}, I{i} );
            elem = setfield(elem,name,value) ;
        end
    
        grouped(i) = elem;
        
    end
    
    
end

% O(n)
function [ I ] = grouped_indices( indices )

	B = unique(indices);
	
	I = cell(1, length(B));
	for i=1:length(B)		 
		I{i} = find(indices == B(i));
	end
       
end