plot_subspaces2.m

一个用EM算法的源程序

% Code for rendering two dimensional results generated by the gpca
% algorithm.  Users should call plot_subspaces
function pl = plot_subspaces2(data, labels, groupBases, basisDimensions)

CENTER_DATA = false;

% Generate a list, existList, of labels that have had points assigned to them.
highestLabel = max(labels);
existList = zeros(highestLabel, 1);  % existList will have at most highestLabel elements.
groupCount = 0;
for labelIndex = 1:highestLabel,
    if (sum(labels == labelIndex) > 0) % If the group has at least one element in it,
        groupCount = groupCount + 1;
        existList(groupCount) = labelIndex;
    end;
end;
existList = existList(1:groupCount);

markers = '.ox+*svp^h<>'; markerCount = length(markers); markerIndex = 1;
colors = 'rbgmcyk'; colorCount = length(colors); colorIndex = 1;

% Hold while drawing a bunch of elements to the current figure.
originalHoldState = ishold;
hold on;

% Iterate through every group that contains at least one element.
for groupIndex = 1:groupCount,
    
    %     % Plot the data points in the current group with unique colors and shapes.
    %     groupDataIndices = find(labels == existList(groupIndex));
    %     pl = plot(data(1, groupDataIndices),data(2,groupDataIndices), ['.' colors(colorIndex)]); 
    %         set(pl,'MarkerSize',5);
    
    basis = groupBases{existList(groupIndex)}(:,1:basisDimensions(existList(groupIndex))); 
    groupData = data(:, labels == existList(groupIndex));
    center = mean(groupData,2);
    
    if (size(basis,2) ~= 1),
        error('Trying to plot a subspace of dimension other than one in a two dimensional subsspace');
    end
    
    
    % Plot the one dimensional subspace (line)
    x = basis(1); 
    y = basis(2);
    
    if(CENTER_DATA),
        projected_data = (groupData' - ones(size(groupData , 2) , 1) * center') * basis;
        upper_bound = max(projected_data) * basis + center;
        lower_bound = min(projected_data) * basis + center;
        l = line([upper_bound(1) lower_bound(1)], [upper_bound(2) lower_bound(2)]);
        set(l, 'Color', colors(colorIndex));
        set(l, 'LineWidth', 3);
    else
        projected_data = (groupData') * basis;
        upper_bound = max(projected_data) * basis;
        lower_bound = min(projected_data) * basis;
        l = line([upper_bound(1) lower_bound(1)], [upper_bound(2) lower_bound(2)]);
        set(l, 'Color', colors(colorIndex));
        set(l, 'LineWidth', 3);
    end

    % Advance to the next color and marker.
    markerIndex = markerIndex + 1; if (markerIndex > markerCount) markerIndex = 1; end;
    colorIndex = colorIndex+1; if (colorIndex > colorCount) colorIndex = 1; end;
end;

xlabel('axis 1')
ylabel('axis 2')

pl = [];