mappinganalysis.m

这个是支持向量聚类机用matlab编译的主程序和部分子程序

%=====================================================================
%
%   MappingAnalysis
%   ----------------
%
%   Parameters:   
%		Samples         - This matrix holds the data points.
%		R		        - The minimal sphere's radius.
%		beta 	        - The vector of the Lagrangian multipliers.
%		quad	        - The quadratic part of the distace from the sphere's
%					      center.
%       q		        - The width of the gaussian kernel.
%
%	Return Value:
%       grids           - Each layer in this matrix holds a grid mapping for 
%                       - a couple of dimensions.
%       grids_sizes     - The number of points in each grid layer.
%                   
%   Maps the sphere to a 2 dimentional data space, The sphere is separately
%   mapped to all possible couples of dimensions.
%=====================================================================






function [grids, grids_sizes] = MappingAnalysis(Samples,R,beta,quad,q)

[attr,N] = size(Samples);

min_sample = min(Samples');
max_sample = max(Samples');
% the grid size is 31 points in each dimension, varying from max to min.
jump = (max_sample - min_sample)./30;

grids_size = 0;
grids = zeros(31*31,2,attr*attr);
% seperate to all possible 2D spaces.
for attr1 = 1:attr-1
    for attr2 = attr1+1:attr

        x = [min_sample(attr1):jump(attr1):max_sample(attr1)];
        y = [min_sample(attr2):jump(attr2):max_sample(attr2)];

        xnum = length(x);
        ynum = length(y);

        grid_2d = zeros(xnum*ynum,2);
        grid_size = 0;

        % maps the sphere into the current 2D space.
        for i = 1:ynum
            for j = 1:xnum
                z = [x(j);y(i)];
                d = DistFromCenter([Samples(attr1,:);Samples(attr2,:)],N,beta,q,z) + quad;
                if d < R
                    grid_size = grid_size + 1;
                    grid_2d(grid_size,:) = z';
                end
            end
        end

        grids_size = grids_size +1;    
        grids(:,:,grids_size) = grid_2d;
        grids_sizes(grids_size) = grid_size;
        
    end
end